Paint Coverage Calculator UK – How Much Paint Do I Need?
Work out how much paint you need in seconds.
1 litre typically covers 10–12 m², 2.5L covers 25–30 m², and 5L covers 50–60 m². Use the calculator below for an exact result based on your room size and number of coats.
Get accurate litres required and the best mix of tins for walls and ceilings — ideal for bedrooms, lounges, kitchens and hallways.
How to Use the Paint Calculator
Switch between Simple (total area) and Room mode (L × W × H with doors/windows and optional ceiling), enter your coverage per litre, choose number of coats, and include 10% waste for real-world results.
What This Paint Coverage Calculator Covers
This paint calculator estimates:
- Total paintable area (m² or ft²) — walls minus openings, with an optional ceiling
- Litres required based on your product’s stated coverage (m²/L) and 1–3 coats
- Per-coat litres to help plan split days and colour changes
- A suggested tin combination (e.g. 1 × 5 L + 1 × 2.5 L) to minimise leftover
- Optional waste/absorption margin (+10% by default) for rollers, edges and texture
How to Use
- Select Simple to enter a known total area, or choose Room to enter length, width and height.
- In Room mode, tick Ceiling if you’re painting it; add doors and windows to subtract their area automatically.
- Enter your product’s coverage per litre (typical 10–14 m²/L for many emulsions—check the tin).
- Pick number of coats (most interiors need 2). Toggle the +10% waste if your surface is porous or textured.
- Choose the tin sizes you can buy (1, 2.5, 5, 10 L). The tool proposes a mix with the least overage.
Why Coverage Planning Matters
Estimating paint precisely avoids mid-job shortages and expensive over-buying. Accounting for surface porosity, roller losses and number of coats ensures consistent colour and finish while reducing waste and cost.
Typical Coverage & Coats (Guidance)
- Standard interior emulsion: ~10–14 m²/L per coat on smooth, sealed walls
- New plaster / bare drywall: requires a mist coat/primer plus 2 finish coats
- Dramatic colour changes: may need an extra coat or tinted primer
- Textured walls: increase waste margin to 10–15%
Pro Tips for Better Results
- Measure accurately: Wall area is calculated using perimeter × height
- Check the tin: Always use the manufacturer’s m²/L rating
- Batch your paint: Mix tins together for consistent colour
- Choose the right roller: Longer nap uses more paint but covers rough surfaces better
- Keep a small reserve: Avoid running short mid-project
Related Tools & Gear
Whether you’re painting a single wall or a full house, this paint coverage calculator gives fast, reliable estimates so you can plan properly and avoid waste.
Calculate Paint Required.
Enter your area (simple or room mode), paint coverage per litre and coats. We’ll estimate litres needed and the best mix of tin sizes.
Total area
Litres required
Suggested tins
Per-coat litres
Notes
- Coverage varies by product, colour and surface. Always check the tin.
- Highly porous, new plaster or dramatic colour changes may need extra coats.
- Round up if you plan touch-ups or feature walls.
Tips
- Working out paint coverage? Use tools like laser levels to keep lines straight and accurate.
- Prepare surfaces properly with quality decorating supplies for a smoother, longer-lasting finish.
- Measure carefully before starting to avoid waste and ensure you buy the right amount of paint.
- Confirm coverage and drying time on the paint tin (coverage varies by finish and surface).
- On new plaster or porous walls, apply a mist coat or suitable primer first.
- Better rollers and brushes often improve finish and reduce paint waste. View decorating supplies
- Prepping surfaces or fitting fixtures? Make sure tools and batteries are ready. View power tool batteries
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Frequently Asked Questions
How much area does 1 litre of paint cover?
Most interior paints typically cover around 10–12 square metres per litre on a smooth surface. Coverage can vary depending on the paint type, wall texture, and how absorbent the surface is. Always check the manufacturer’s recommendation on the tin for the most accurate coverage estimate. How much paint do I need for a room? || To estimate paint needed for a room, measure the wall width and height to calculate the total wall area in square metres. Subtract doors and windows, then divide the remaining area by the paint coverage rate per litre. Many decorators also allow extra paint for a second coat. How much area does 2.5 litres of paint cover? || A 2.5 litre tin of paint will usually cover approximately 25–30 square metres for one coat, depending on the paint type and surface condition. Rough or porous walls may require more paint and may also need a second coat. Do I need two coats of paint? || Most decorating jobs require at least two coats to achieve an even finish and full colour coverage. The first coat often acts as a base layer, especially when painting over darker colours or newly plastered surfaces. Does wall texture affect paint coverage? || Yes, rough or textured surfaces such as brick, plaster, or heavily patterned walls absorb more paint and reduce coverage per litre. Smooth plastered walls generally provide the best coverage and require less paint overall.
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