Paint Calculator
Work out how much paint you need for a room, including multiple coats and deductions for doors and windows.
≈350 ft²/gal or ≈10 m²/L for emulsion
Your result
Paint needed
1.9 US gallons
In litres
7.2 L
Paintable wall area
331 ft² · 30.8 m²
How paint quantity is worked out
Multiply the total wall width by the height to get the wall area, then subtract openings — this calculator deducts about 1.9 m² (20 ft²) per door and 1.5 m² (16 ft²) per window. Multiply by the number of coats and divide by the coverage on the tin.
Most interior emulsions cover around 10–12 m² per litre (350–400 ft² per gallon) on smooth, primed walls. New plaster, rough surfaces and strong colour changes need more.
Frequently asked questions
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