Paint Calculator
Find out exactly how much paint you need for your room.
How paint coverage is calculated
The calculator finds the total wall area (room perimeter × wall height), subtracts standard allowances for doors (1.9 m² each) and windows (1.2 m² each), then divides by the coverage rate of your chosen paint. The result is multiplied by the number of coats. Coverage rates: standard emulsion ~10 m²/L, thick/textured ~7 m²/L, primer ~8 m²/L.
Frequently asked questions
Should I include the ceiling?
This calculator covers wall area only. For ceilings, add another calculation using length × width as a separate flat surface. Ceilings typically need one coat of white ceiling paint.
Why does the result suggest rounding up to 2.5 L tins?
Paint is sold in standard tin sizes (1L, 2.5L, 5L, 10L). Buying the nearest size that covers your area avoids running short. Having a little extra is also useful for touch-ups later.
