Paint Calculator

Where to Buy Paint in the UK

Paint prices vary significantly between retailers. Buying online often saves 10–20% compared to in-store prices, and most major retailers offer free click-and-collect. Compare these trusted UK suppliers before committing.

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How Much Paint Do I Need?

It is one of the most common questions in home improvement, and one of the easiest to get wrong. Buy too little and you are back at the shop mid-project with a wet roller and drying paint edges. Buy too much and you end up with half-used tins gathering dust in the garage for years. Neither outcome is ideal, which is exactly why this calculator exists.

The formula for working out how much paint you need is straightforward. You calculate the total area of the surfaces you want to paint, deduct the areas you will not paint (doors, windows, built-in wardrobes), multiply by the number of coats, divide by the paint's coverage rate and add a small allowance for wastage. It sounds like a lot of steps, but our calculator does every one of them in under a second.

The key variable most people overlook is the coverage rate — the number of square metres one litre of paint will cover. This varies significantly depending on the type of paint. Standard wall emulsion covers approximately 12 m² per litre. Ceiling matt covers slightly less at around 11 m² per litre because ceilings are harder to apply paint to evenly and tend to require a thicker coat. Eggshell (used for woodwork like skirting boards and door frames) covers around 14 m² per litre because it is applied more thinly. Gloss, which is self-levelling and spread very thin, covers approximately 16 m² per litre.

These coverage rates assume a smooth, previously painted surface in reasonable condition. If you are painting onto new plaster, bare wood, or a very rough textured surface, the actual coverage can be 20–40% less than the quoted rate. New plaster in particular is highly absorbent and requires a dedicated mist coat (emulsion diluted 50/50 with water) before you can apply full-strength paint.

The other factor that catches people out is the number of coats. Two coats is the minimum for a professional-looking finish with even colour and no patchiness. If you are painting a light colour over a dark wall, expect to need three coats — or apply a coat of white primer first, followed by two topcoats. Going from dark to light without enough coats is the number one reason for patchy, uneven paint jobs in UK homes.

Quick Reference: Paint for a Standard UK Room

To give you a ballpark before you use the calculator, here are the typical paint quantities for a standard UK room (4m × 3.5m, 2.4m ceiling height, one door, one window, two coats of emulsion):

That means a mid-range Dulux job on walls and ceiling for a typical room will cost approximately £112 in paint alone (4 tins at £28 each). With Farrow & Ball, the same room jumps to £208. Budget paint brings it down to around £60.

Paint Coverage Rates UK

Coverage rate is the single most important number when calculating how much paint to buy. It tells you how many square metres one litre of paint will cover on a smooth, previously painted surface with good opacity. Every reputable UK paint brand prints this figure on the tin — but it varies by paint type, finish and brand quality.

The table below summarises the typical coverage rates you can expect in 2026 for each major paint type sold in the UK. These figures assume a prepared surface — clean, dry and in good condition. If the surface is porous, textured, or unpainted, reduce the effective coverage by 20–40%.

Factors That Reduce Coverage

The quoted coverage rate on a paint tin is a best-case figure. In practice, several factors can reduce how far your paint goes:

• Surface porosity: New plaster, bare wood and fresh render absorb paint like a sponge. Expect to use 30–50% more paint on the first coat of an unsealed surface compared to a previously painted wall.
• Surface texture: Heavily textured wallpaper, Artex ceilings and rough-rendered walls have a greater surface area than smooth plaster. Coverage can drop by 20–30% on these surfaces.
• Application method: Rollers generally use paint more efficiently than brushes. Spray application gives the most even finish but can use 20–30% more paint due to overspray.
• Colour change: Painting a light colour over a dark base requires more coats (and therefore more paint) to achieve full opacity. Red, navy and dark grey are particularly difficult to cover.
• Paint quality: Cheaper paints often contain fewer pigments and more fillers, meaning lower opacity per coat. A premium paint might achieve full coverage in two coats where a budget paint needs three.
• Wastage: Spillage, loaded rollers, paint left in trays and roller covers, and cutting-in around edges all contribute to wastage. A 10% allowance is standard; inexperienced DIYers should budget 15%.

How to Measure a Room for Paint

Accurate measurements are the foundation of a good paint estimate. Measure once, buy right. Here is the step-by-step process professional decorators use.

Step 1: Measure Each Wall

Use a tape measure (a 5-metre retractable tape is ideal) to measure the length of each wall at floor level. For a rectangular room, you only need two measurements — length and width — because opposite walls are the same. For L-shaped rooms, break the space into rectangles and measure each section separately.

Write the measurements down immediately. Do not try to remember them. A small notepad or your phone's notes app is fine. Record measurements in metres to one decimal place (for example, 4.2m not 4m or 420cm).

Step 2: Measure the Ceiling Height

Measure from the floor to the ceiling in at least two places. In older UK properties, floors and ceilings may not be perfectly level, so take the higher measurement to ensure you do not underestimate. The standard ceiling height in UK homes built after 1960 is 2.4 metres. Victorian and Edwardian houses often have ceilings at 2.7–3.0 metres, which means significantly more wall area and therefore more paint.

Step 3: Count and Measure Doors

Count every door in the room. A standard UK interior door is approximately 1981mm × 762mm (6 ft 6 in × 2 ft 6 in), which gives an area of roughly 1.5 m². However, including the door frame and architrave surround, the total opening you deduct from the wall area is approximately 1.8 m² per door. Our calculator uses this standard deduction.

If you have wider-than-standard doors (such as double doors to a living room or sliding patio doors), measure the actual opening width and height and multiply. A standard patio door set is roughly 1.8m wide × 2.1m tall = 3.8 m².

Step 4: Count and Measure Windows

A standard UK window opening (including the frame and sill) is approximately 1.2 m². This is the default deduction in our calculator. Larger bay windows, picture windows or floor-to-ceiling windows should be measured individually. Measure the width and height of the full window opening — including the frame — and multiply.

Step 5: Calculate Total Wall Area

For a simple rectangular room:

Total wall area = 2 × (length + width) × ceiling height
Paintable area = total wall area - (doors × 1.8) - (windows × 1.2)

For example, a room measuring 4.0m × 3.5m with 2.4m ceilings, one door and two windows:

Total wall area = 2 × (4.0 + 3.5) × 2.4 = 36.0 m²
Paintable area = 36.0 - (1 × 1.8) - (2 × 1.2) = 31.8 m²

Step 6: Measure the Ceiling (If Painting It)

The ceiling area is simply the room length multiplied by the room width. For our example room: 4.0 × 3.5 = 14.0 m². Ceiling paint is formulated differently from wall emulsion — it is thicker to reduce drips — so use the ceiling matt coverage rate (approximately 11 m²/litre) rather than the wall emulsion rate.

Step 7: Measure Woodwork (Optional)

If you are also painting skirting boards, door frames, window frames and picture rails, measure the total linear metres and multiply by the height. Standard UK skirting boards are 120–150mm tall. For a room with a 15-metre perimeter, that is roughly 15m × 0.15m = 2.25 m² of skirting. Add door architraves (approximately 0.5 m² per door frame, both sides) and window surrounds. Woodwork paints (eggshell, satinwood, gloss) have higher coverage rates, so even a large room's woodwork rarely needs more than one 2.5-litre tin.

UK Paint Prices 2026

Paint prices in the UK range from under £10 for a basic own-brand emulsion to over £50 for premium heritage brands. The table below gives you a comprehensive comparison of what you can expect to pay in 2026 across budget, mid-range and premium tiers. Prices are typical RRP for matt emulsion (the most commonly purchased type) in standard white and popular colours.

Budget Paint (Under £20 per 2.5L)

Mid-Range Paint (£20–£35 per 2.5L)

Premium Paint (Over £35 per 2.5L)

Woodwork Paint Prices

Money-saving tip: Dulux and Crown frequently run promotions at B&Q and Wickes — "3 for 2" or 25% off — especially during bank holiday weekends. Signing up for retailer loyalty cards (B&Q Club, Wickes Trade Card) can unlock further discounts. Also check Amazon UK where standard Dulux tins are often 15–20% cheaper than in-store RRP, particularly on 5-litre sizes.

DIY vs Professional Painting Costs UK

Should you paint the room yourself or hire a professional? The answer depends on your budget, available time, the complexity of the job and how much you value a flawless finish. Here is a realistic comparison of costs and outcomes.

Professional Painter Rates (2026)

What Does a Professional Include?

A good professional painter and decorator will typically include the following in their quote: moving light furniture, covering floors and remaining furniture with dust sheets, washing walls with sugar soap, filling small cracks and holes, sanding between coats, two coats of emulsion on walls and ceiling, and a clean-up at the end. Some painters include materials in their quote while others charge for labour only — always clarify before agreeing.

How Many Rooms Can a Painter Do Per Day?

An experienced painter can typically complete one standard room per day (walls and ceiling, two coats, including prep). This assumes the room is in reasonable condition and does not need extensive filling, stripping or priming. Larger rooms, high ceilings or rooms requiring wallpaper removal will take longer. A hallway and landing typically takes 1.5–2 days. Painting the exterior of a semi-detached house takes 3–5 days.

Full Cost Comparison: One Standard Room

When to Hire a Professional

Hiring a professional makes sense in several situations. If you have high ceilings (above 3 metres), a stairwell that requires specialist access equipment, extensive preparation work (wallpaper removal, stain blocking, plastering), or simply limited time, a professional will get the job done faster and to a higher standard. Professional painters also tend to achieve a much better finish on woodwork — gloss and eggshell are notoriously unforgiving of poor brush technique.

For straightforward rooms with standard 2.4-metre ceilings and walls in good condition, most competent DIYers can achieve an excellent finish with good-quality paint and proper preparation. The key is to invest time in preparation — cleaning, filling, sanding and priming — rather than rushing to get the roller on the wall.

Finding a Reliable Painter

Always get at least three written quotes. Check that the painter has public liability insurance (minimum £1 million), and ask to see examples of recent work or read online reviews. Checkatrade, MyBuilder and Rated People are the main UK platforms for finding vetted tradespeople. A professional decorator may also hold qualifications such as NVQ Level 2 or 3 in Painting and Decorating, or be a member of the Painting & Decorating Association (PDA).

Common Paint Mistakes to Avoid

Even experienced DIYers make painting mistakes. Here are the most common ones we see — and how to avoid them. Getting these right can save you hours of frustration and the cost of having to redo the job.

1. Skipping Preparation

This is the single biggest mistake. Paint will not adhere properly to a dirty, greasy or flaking surface. Before you open a single tin, wash all walls with sugar soap and warm water, fill any holes and cracks with a lightweight filler (Polyfilla or similar), sand the filled areas smooth when dry, and wipe down with a damp cloth to remove dust. For woodwork, sand existing paint lightly with 120-grit sandpaper to create a key for the new coat. Preparation typically takes as long as the actual painting — but it is what separates a mediocre result from a professional one.

2. Not Buying Enough Paint

Running out of paint mid-wall is a disaster. You will see the join line where wet and dry paint meet, and colour-matched tins from different batches may not be identical. Always buy slightly more than you need — a 10% buffer is standard. Our calculator includes this wastage allowance automatically. Unopened tins can be returned to most UK retailers within 30 days.

3. Buying Too Little or Too Cheap

Budget paint often has lower pigment density, which means less opacity per coat. You might save £15 on the tin but end up needing a third coat — which costs more in paint and takes another half-day of work. Mid-range brands like Dulux Easycare and Crown Breatheasy consistently deliver good coverage in two coats, making them the best value for most projects.

4. Using the Wrong Paint Type

Standard matt emulsion should not be used in bathrooms — it absorbs moisture and encourages mould. Kitchens need a paint that can be wiped clean. Woodwork needs a specialist wood paint (eggshell, satinwood or gloss) not wall emulsion. And ceilings should use ceiling-specific paint which is formulated to be thicker and more drip-resistant. Using the right product for each surface saves time and ensures longevity.

5. Not Using Primer When Needed

Primer is essential on new plaster (use a mist coat), bare wood (use a wood primer), stained surfaces (use a stain-blocking primer like Zinsser Bulls Eye or B-I-N) and when making dramatic colour changes. Skipping primer on these surfaces leads to poor adhesion, bleed-through and uneven colour. On previously painted surfaces in good condition, primer is generally not necessary.

6. Painting in the Wrong Conditions

Ideal painting conditions are 10–25°C with low humidity and good ventilation. Painting in very cold conditions (below 5°C) causes paint to dry too slowly and can prevent proper film formation. Painting in direct sunlight or extreme heat causes paint to dry too quickly, leading to brush marks and lap lines. Humid conditions slow drying and increase the risk of sagging. If you are painting in winter, run the central heating to maintain a consistent room temperature and open a window for ventilation.

7. Applying the Second Coat Too Soon

Patience is essential. Most wall emulsions need 2–4 hours between coats; oil-based woodwork paints need 16–24 hours. Applying the second coat before the first is fully dry traps moisture, causes the paint to lift and results in a patchy finish. Always check the drying time on the tin and add extra time in cold or humid weather.

8. Poor Cutting-In Technique

Cutting in — painting the edges where the roller cannot reach — is the part that separates a good paint job from a bad one. Use a 2-inch angled brush, load it lightly, and paint a smooth line along corners, ceiling edges, door frames and window frames before rolling the main area. Work in sections of 1–2 metres so the cut-in edge is still wet when you roll up to it. If the cut-in dries before the roller meets it, you will see a visible band of different texture.

9. Overloading the Roller

Dipping the roller too deep into the tray and not removing the excess leads to drips, splatters and an uneven coat. Load the roller by rolling it in the shallow end of the tray, then roll back and forth on the ramp section to distribute paint evenly before applying to the wall. The roller should be evenly coated but not dripping.

10. Not Protecting the Room

Cover all furniture and the floor with dust sheets before you start. Remove light switch covers and socket covers (after turning off the electricity at the consumer unit). Use masking tape along edges you want to protect — ceiling lines, skirting boards, window glass. The 15 minutes you spend masking saves hours of cleaning paint off surfaces later. Use proper painter's masking tape (such as FrogTape) rather than cheap tape, which can bleed and leave adhesive residue.

Best Paint Brands UK 2026

With hundreds of paint brands available in the UK, choosing the right one can feel overwhelming. Here is an honest assessment of the leading brands based on coverage, durability, colour range and value for money.

Dulux

Dulux is the UK's best-selling paint brand and the default choice for most homeowners. The Easycare range is the standout product — it is washable, stain-resistant and covers well in two coats. Dulux offers over 700 colours through their colour-mixing service at B&Q, Wickes and independent decorating shops. The Trade range (particularly Trade Vinyl Matt) is a step above the retail products with better coverage and is widely used by professional decorators. Dulux also offers a colour visualiser app that lets you preview colours on your walls using your phone's camera.

The main downside is price — Dulux Easycare has crept up to around £28 per 2.5L tin, making it one of the pricier mid-range options. However, the coverage rate of 13 m²/litre means you often need fewer tins than budget brands, which partially offsets the higher unit cost. For most UK homes, Dulux remains the best all-round choice.

Crown

Crown is Dulux's main rival in the mid-range segment. The Breatheasy range is its flagship — a low-VOC emulsion that is better for indoor air quality and particularly good for households with allergies, asthma or young children. Coverage and durability are comparable to Dulux Easycare, but Crown is typically £2–£3 cheaper per tin. Crown's Kitchen & Bathroom paint is one of the best moisture-resistant paints on the market, with strong anti-mould properties.

Crown's colour range is not quite as extensive as Dulux's, but with 400+ colours it covers all the popular shades. Application is smooth and it does not have the slight chemical smell some users notice with Dulux. An excellent alternative if you want to save a few pounds without sacrificing quality.

Farrow & Ball

The premium heritage brand that has become a status symbol in UK interiors. Farrow & Ball paints are made in Dorset, England, and are known for their extraordinary depth of colour. The pigment load is exceptionally high, which gives their paints a richness that mid-range brands simply cannot match. Popular colours like Elephant's Breath, Hague Blue and Railings have become design classics.

At £52 per 2.5L tin, Farrow & Ball is expensive — roughly double the price of Dulux. Coverage is average (12 m²/litre), so you do not save on quantity. The Modern Emulsion range is washable and more durable than the traditional Estate Emulsion. The main justification for the premium is the colour quality — if colour accuracy and depth matter to you (and they do in feature walls, living rooms and bedrooms), Farrow & Ball delivers a finish that cheaper paints cannot replicate.

Little Greene

Often described as "the thinking person's Farrow & Ball," Little Greene is a British paint company with a 300-year history. Their Intelligent range — including Intelligent Matt Emulsion and Intelligent Eggshell — is notable for being both washable and beautifully flat, which is difficult to achieve. Prices are slightly lower than Farrow & Ball (around £48 per 2.5L) with comparable colour depth. Little Greene's colour cards are organised historically — Georgian, Regency, Victorian, mid-century — making them a favourite among period property owners.

Johnstone's

The best budget brand in the UK. Johnstone's paints are manufactured in the UK and widely available at independent decorating shops, B&Q and Amazon. Coverage is decent at 12 m²/litre and the price (£14 per 2.5L) makes it roughly half the cost of Dulux. The colour range is more limited, but for large-area jobs where cost is the priority — landlord repaints, rental properties, garages, utility rooms — Johnstone's is hard to beat.

Leyland Trade

Another strong budget option, particularly in the trade range. Leyland Trade Vinyl Matt is a professional decorator's go-to for large commercial jobs and landlord repaints. At £15 per 2.5L (or approximately £24 per 5L), it offers excellent coverage (12–14 m²/litre) and a clean, flat finish. It is not washable in the way Dulux Easycare is, but for ceilings and rooms that do not get heavy traffic, it performs admirably.

Earthborn

For eco-conscious homeowners, Earthborn is the standout brand. Their Claypaint is made from natural clay and mineral pigments with zero VOCs — meaning no chemical smell during or after application. It is breathable (allowing moisture to pass through the wall), which makes it excellent for period properties with solid walls. At £42 per 2.5L, it sits in the premium tier. Coverage is slightly lower (10–11 m²/litre) due to the clay-based formula. The finish is a distinctive ultra-flat matt with a soft, chalky texture that photographs beautifully.

Brand Comparison at a Glance

Paint Types Explained: Matt, Silk, Eggshell, Satinwood & Gloss

Choosing the right paint finish is just as important as choosing the right colour. Each finish has different properties that make it suitable for specific rooms and surfaces. Here is a comprehensive guide to every paint type you will encounter in a UK decorating shop.

Matt Emulsion

Matt emulsion is the most popular wall paint in UK homes. It has a flat, non-reflective finish that diffuses light evenly across the surface. This makes it excellent at hiding minor surface imperfections — small bumps, filler repairs and slightly uneven plaster are far less visible under matt paint than under any sheen finish.

Best for: Living rooms, bedrooms, dining rooms and ceilings. Any room where a calm, sophisticated finish is desired.

Not ideal for: High-traffic areas, kitchens and bathrooms. Standard matt emulsion is not washable — scuff marks and fingerprints are difficult to remove without marking the surface. For these rooms, use a dedicated washable matt (like Dulux Easycare) or upgrade to silk.

Silk Emulsion

Silk emulsion has a soft, subtle sheen that reflects light gently, making rooms feel slightly brighter and more spacious. The sheen also makes the surface wipeable — you can clean off fingerprints, scuff marks and light splashes with a damp cloth without damaging the finish.

Best for: Hallways, staircases, children's rooms, kitchens (if not using dedicated kitchen paint) and any room that gets heavy traffic or is likely to need regular cleaning.

Not ideal for: Walls with imperfections. The reflective finish highlights every bump, dip and filler patch. If your walls are not perfectly smooth, matt is a more forgiving choice.

Soft Sheen

Soft sheen sits between matt and silk — a very slight sheen that is more wipeable than matt but less reflective than silk. It is sometimes described as "low-sheen" or "mid-sheen." This makes it a versatile compromise for rooms where you want some washability without the obvious shine of silk.

Best for: Hallways, landings, older children's bedrooms and open-plan living spaces.

Eggshell

Eggshell is primarily a woodwork paint, though it can be used on walls for a subtle, sophisticated look. It has a low-lustre, slightly satin finish — roughly 10–20% sheen, compared to gloss at 70–80%. Modern water-based eggshell (like Farrow & Ball Estate Eggshell or Little Greene Intelligent Eggshell) has become the fashionable choice for skirting boards, door frames and built-in furniture, replacing high-gloss in many contemporary and period-style interiors.

Best for: Skirting boards, door frames, window frames, built-in shelving, radiators (use a specialist radiator version). Also works well on walls in kitchens and bathrooms where a subtle sheen and washability are needed.

Key advantage: Eggshell does not yellow over time the way traditional oil-based gloss does. It dries quickly (1–2 hours), has minimal odour and cleans up with water.

Satinwood

Satinwood has a slightly higher sheen than eggshell — approximately 25–40% — giving a smooth, gently lustrous finish. It is the middle ground between eggshell and gloss. Traditional satinwood was oil-based, but most modern UK versions are water-based for easier application and faster drying.

Best for: Woodwork where you want a bit more sheen than eggshell but less than full gloss. Popular for skirting boards, banisters and door frames in homes that want a slightly more traditional look without the full gloss shine.

Gloss

Gloss paint has the highest sheen level (70–80% reflectivity) and gives a hard, shiny, durable finish. It was the traditional choice for all woodwork in UK homes for decades and remains popular, particularly for external woodwork where maximum durability is needed. Gloss is available in both oil-based (solvent-based) and water-based formulations.

Oil-based gloss gives a deeper shine and harder finish but takes 16–24 hours to dry, has a strong chemical smell and requires white spirit for brush cleaning. It also yellows over time, particularly on white-painted surfaces in rooms without much natural light.

Water-based gloss dries in 1–2 hours, has minimal odour and does not yellow. However, it does not achieve quite the same depth of shine as oil-based and is slightly less hard-wearing. For most interior woodwork, water-based gloss is now the preferred choice.

Best for: Front doors, exterior window frames, banisters and any woodwork that needs maximum durability and a high-shine traditional finish.

Not ideal for: Walls (gloss on walls looks institutional), or surfaces with imperfections (the high shine highlights every flaw).

Primer and Undercoat

Primer and undercoat are preparation coats applied before the topcoat. They serve different purposes:

• Primer seals porous surfaces (new plaster, bare wood, MDF) and creates a uniform base for the topcoat to adhere to. Without primer, the topcoat will be absorbed unevenly, leading to a patchy finish.
• Undercoat builds opacity and provides a smooth, uniform-colour base — particularly important when covering a dark colour with a light one, or when using a topcoat that is not fully opaque.
• Combined primer/undercoat products (like Dulux Trade Undercoat or Zinsser Bulls Eye 1-2-3) do both jobs in one coat and are the most convenient option for most DIY projects.

On new plaster, use a mist coat (50/50 emulsion and water) instead of a dedicated primer. On bare wood, use a specialist wood primer. On stained surfaces (water marks, smoke damage, marker pen), use a stain-blocking primer like Zinsser B-I-N (shellac-based) or Zinsser Bulls Eye 1-2-3 (water-based).

Kitchen and Bathroom Paint

These are specialist wall paints formulated for high-moisture environments. They typically have a soft sheen or mid-sheen finish (not flat matt), contain anti-mould and anti-bacterial additives, and have a moisture-resistant film that prevents condensation from penetrating the paint surface. Dulux Easycare Bathroom, Crown Breatheasy Bathroom and Johnstone's Kitchen & Bathroom are the leading UK options. They cost £2–£5 more per tin than standard emulsion but save you from having to repaint mouldy walls every 12–18 months.

Masonry Paint

Masonry paint is for external walls — brick, render, pebbledash and concrete. It is formulated to be weatherproof, UV-resistant and flexible enough to cope with thermal expansion and contraction. Coverage is much lower than interior paints (6–8 m²/litre on rough render) due to the textured surfaces involved. Sandtex, Dulux Weathershield and Johnstone's Stormshield are the main UK brands. Expect to pay £30–£50 per 5-litre tin.

Choosing the Right Finish: Room-by-Room Guide

How to Paint a Room: Step-by-Step Guide

Whether you are a first-time DIYer or a seasoned decorator, following a systematic approach ensures the best results. Here is the complete process from start to finish.

What You Will Need

Before you start, gather all your materials and tools. There is nothing worse than having to stop mid-project because you forgot a dust sheet.

• Paint — the correct type and quantity (use our calculator above)
• Roller frame and sleeve — 9-inch medium-pile for walls, short-pile for ceilings, small 4-inch for tight spaces
• Paint tray (or a 5-litre scuttle for larger jobs)
• 2-inch angled brush for cutting in
• 1-inch brush for fine detail and woodwork
• Masking tape — FrogTape for clean lines
• Dust sheets — cotton for floors (they absorb drips), plastic for furniture
• Sugar soap and sponge for cleaning walls
• Lightweight filler and a filling knife
• Fine sandpaper (120-grit for walls, 240-grit for woodwork)
• Step ladder or platform
• Screwdriver — to remove light switch and socket covers
• Extension pole — for reaching ceilings and high walls without a ladder

All of these items are available at Amazon UK, B&Q or Wickes. A complete decorating kit (roller, tray, brushes, tape, dust sheet) costs £15–£25.

Step 1: Clear and Protect the Room

Move all furniture to the centre of the room or out of the room entirely. Cover remaining furniture with plastic dust sheets and cover the entire floor with cotton dust sheets (they stay in place better than plastic and absorb drips). Remove curtains, light fittings and any wall decorations. Unscrew light switch and socket covers (after turning off the electricity at the consumer unit) and put the screws in a labelled bag.

Step 2: Clean the Walls

Wash all walls with sugar soap solution — this removes grease, nicotine, dust and cobwebs that would prevent paint from adhering. Pay particular attention to areas around light switches, above radiators and in kitchens where cooking grease accumulates. Rinse with clean water and allow to dry completely (at least 2–3 hours, or overnight in cold weather).

Step 3: Fill and Sand

Fill any holes, cracks and dents with lightweight filler. Apply with a filling knife, slightly overfilling the repair. Once dry (usually 1–2 hours), sand flush with 120-grit sandpaper. For larger repairs, apply filler in two thin layers rather than one thick one to prevent cracking. Sand the entire wall surface lightly to create a key for the new paint — you do not need to remove all the old paint, just scuff the surface. Wipe down with a damp cloth to remove sanding dust.

Step 4: Mask Off Edges

Apply masking tape along the ceiling line, around door frames, window frames, skirting boards and any areas where two colours meet. Press the tape edge firmly to prevent paint bleeding underneath. FrogTape is the gold standard — its paint-block technology creates a micro-barrier that prevents bleed. Remove tape while the final coat is still slightly tacky for the cleanest lines.

Step 5: Prime (If Necessary)

Apply primer to any bare surfaces — new plaster (mist coat), bare wood (wood primer), repaired filler patches (a quick coat of diluted emulsion or primer). If you are making a dramatic colour change, apply one coat of white primer over the entire surface to create a neutral base. Allow primer to dry fully before applying the topcoat.

Step 6: Cut In First

Using a 2-inch angled brush, paint a 50–75mm strip along all edges — ceiling line, corners, around door and window frames, along skirting boards and around sockets/switches. Work in sections of 1–2 metres at a time so the cut-in edge stays wet until you can blend it with the roller. Load the brush lightly — dip only the bottom third of the bristles into the paint and tap off the excess on the side of the tin.

Step 7: Roll the Walls

Load the roller evenly from the tray and apply paint in a large W or M pattern on the wall, then fill in with parallel strokes. Work from top to bottom in vertical strips approximately 1 metre wide, maintaining a wet edge at all times. Do not press too hard — let the roller do the work. Reload before each new strip. On the first coat, the existing colour may show through — this is normal with two-coat systems.

Step 8: Second Coat

Wait for the first coat to dry completely (check the tin — usually 2–4 hours for emulsion). Repeat the cutting-in and rolling process for the second coat. The second coat should give full, even coverage with consistent colour. If any areas still look thin, apply a targeted third coat rather than going over the entire wall again.

Step 9: Paint the Ceiling

If painting the ceiling, do it before the walls (or at the same time as the first wall coat, since any splashes on the walls will be covered by the wall paint). Use an extension pole to avoid working on a ladder all day. Apply ceiling paint in strips, working away from the main light source to minimise visible roller marks. Two coats is standard for ceilings.

Step 10: Paint Woodwork Last

Woodwork (skirting boards, door frames, window frames, doors) should be painted after the walls and ceiling are complete. This ensures any wall paint that overlaps onto the woodwork gets covered by the final woodwork coat. Sand woodwork lightly with 240-grit sandpaper before painting. Apply eggshell, satinwood or gloss with a 2-inch brush, working in the direction of the wood grain. For doors, paint the panels first, then the cross rails, then the stiles (vertical edges). Two coats is standard.

Step 11: Clean Up

Remove masking tape while the final coat is still slightly tacky. Peel slowly at a 45-degree angle for clean lines. Clean rollers and brushes immediately — water-based paints wash out with warm water. Wrap unused rollers in cling film if you plan to continue the next day (this prevents them drying out without needing to wash them). Refit light switches, socket covers and curtain poles once everything is dry. Fold up dust sheets carefully to contain any dried paint flakes.

Painting Tips from Professional Decorators

We asked experienced UK painters and decorators for their top tips — the tricks of the trade that make a real difference to the finished result.

• Box your paint: If you are using more than one tin of the same colour, pour them all into a large bucket and mix thoroughly before starting. This eliminates any slight batch-to-batch colour variation and ensures perfectly consistent colour across the room. Professionals call this "boxing."
• Condition new rollers: New roller sleeves shed fibres on the first use. Before loading with paint, wrap the roller in masking tape, peel it off, then rinse the sleeve under running water and spin dry. This removes loose fibres that would otherwise end up in your finish.
• Use the right roller nap: Short nap (5–6mm) for smooth surfaces and ceilings. Medium nap (9–12mm) for standard plastered walls. Long nap (18mm+) for textured surfaces and rough render. Using the wrong nap wastes paint and gives a poor finish.
• Maintain a wet edge: Never stop mid-wall. Always work from one corner to the other in a continuous flow, keeping the edge of each roller strip wet. If you stop and let an edge dry, the overlap will be visible as a darker band in the finished coat.
• Light matters: Set up temporary lighting (a portable work lamp) in the room before you start. Painting by poor light means you cannot see thin spots, drips or missed patches until the light changes — by which time the paint is dry.
• Temperature matters: Paint a room that is at a comfortable temperature — between 15–20°C is ideal. Cold rooms slow drying and affect adhesion. Hot rooms cause paint to dry too fast, making it hard to blend edges.
• The order matters: Always paint ceiling first, then walls, then woodwork. This way, any drips or overlaps from the previous surface are covered by the next one. Within woodwork, paint skirting boards last (after door and window frames) because they are at floor level and most prone to damage from foot traffic and cleaning.
• Invest in good brushes: A £3 brush from a budget shop will leave bristle marks, shed hairs into your paintwork and be unusable after one job. A good-quality brush (£8–£15 from Purdy, Hamilton or Harris) gives a smoother finish, holds more paint and lasts for years if cleaned properly. Professional decorators often use the same favourite brush for decades.

Frequently Asked Questions

How Our Paint Calculator Works

Our calculator uses the following methodology and assumptions. Understanding these helps you adjust the results for your specific situation.

Area Calculation

The calculator computes total wall area using the formula: 2 × (length + width) × ceiling height. This works for standard rectangular rooms. For L-shaped rooms, calculate each rectangular section separately and add the results. For rooms with alcoves or chimney breasts, measure each wall individually and total them.

Deductions

Each door is deducted at 1.8 m² (the standard UK interior door plus frame). Each window is deducted at 1.2 m² (the average UK window opening). If your doors or windows are significantly larger than standard (such as patio doors or floor-to-ceiling windows), you may want to manually adjust the result downward.

Coverage Rates

We use the following coverage rates, which represent mid-point values for major UK brands on smooth, previously painted surfaces:

• Wall Emulsion: 12 m² per litre
• Ceiling Matt: 11 m² per litre
• Eggshell (woodwork): 14 m² per litre
• Gloss (woodwork): 16 m² per litre

Wastage Allowance

The calculator adds a 10% wastage allowance to the calculated litres. This accounts for paint left in roller covers, trays, tins and minor spillage. For first-time DIYers, consider increasing this mentally to 15%.

Tin Sizes

Results are rounded up to the nearest 2.5-litre tin, which is the standard retail size in the UK. Most brands also sell 5-litre tins (better value per litre) and 750ml tins (for small areas or tester quantities). If the calculator shows 3 tins, you could instead buy one 5L and one 2.5L for a slight saving.

Ceiling Area

When "Ceiling Matt" is selected as the paint type, the calculator uses length × width as the area instead of the wall area formula. This gives you the ceiling-only quantity. To calculate both walls and ceiling together, run the calculator twice — once with "Wall Emulsion" selected and once with "Ceiling Matt."

Pricing

The estimated cost is based on the price per 2.5-litre tin at the selected quality level: Budget (£15), Mid-Range (£28) and Premium (£52). These are 2026 average retail prices. Actual prices vary by colour, retailer and any ongoing promotions. The cost shown is for paint only — it does not include brushes, rollers, tape, dust sheets or other preparation materials.