Paint Calculator
Enter your room's length, width and wall height, take off doors and windows, and pick the number of coats to see how much paint to buy.
Your details
Result
Paint needed
7.0 L
7.7 L with a 10% allowance
- Wall area
- 41.9 m²
- Coverage assumed
- 12 m² per litre per coat
- Doors count as 1.9 m² and windows as 1.2 m². The ceiling is not included. Rough walls and dark colours use more.
Good to know: A 4 m × 5 m room with 2.5 m walls needs about 7 litres for two coats, or 7.7 litres with a 10% allowance.
Please note: Estimates only. Measure your actual space, buy a little extra, and check product labels, safety requirements and local building rules. Do not rely on this for structural or safety-critical work.
About this tool
Calculate paint needed based on wall area and coverage rate — for home decorating and painting projects.
Formula
Paint (liters) = wall area ÷ coverage per liter × number of coats. Typical coverage: 10-12 m² per liter.
Reference values
- 1 liter covers ≈ 10-12 m² per coat
- Most walls need 2 coats
- 1 gallon covers ≈ 350-400 sq ft per coat
Questions people ask
How much does a litre of paint cover?
About 10 to 12 m² per coat, but check the tin. Rough walls and dark colours use more.
How many coats do I need?
Two for most walls. Covering a dark colour with a light one may need three or a primer.
Should I paint the ceiling too?
This calculator covers the walls. Add ceiling area separately.
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How we calculate this
We use the standard published formula or definition for this calculation, and we show the working so you can check it.
Spotted a mistake? Tell us and we'll check it. How we check our calculators