Mondo Knows Tools
Paint Coverage Calculator
How much paint a room needs, in litres, gallons and cans. Use the free paint coverage calculator below to get an instant answer, with the formula shown so you can check the maths and trust the result. Free, private, and no sign-up.
Square metres per litre (metric) or square feet per gallon (imperial).
Litres per can, or gallons per can.
Mondo says
Paint needed for 2 coats
6.7 L
Painting34 m² of wall
Wall area before openings38 m²
Doors and windows− 5 m²
With coats67 m²
Cans of 2.5 L3
Left over0.8 L
Buy one extra small can for touch-ups, and remember a strong colour over a light wall often needs three coats.
How it works
Measure the room once and this works out the paintable wall area, takes off the doors and windows so you are not buying paint for glass, multiplies by the number of coats and divides by the coverage printed on the tin. Two coats is the honest default for a colour change.
The formula
Wall area = perimeter × height − openings. Paint needed = (wall area × coats) ÷ coverage per litre.Paint Coverage Calculator: common questions
- What does the Paint Coverage Calculator work out?
- How much paint a room needs, in litres, gallons and cans. It is one of the Everyday & Tech tools on Mondo Knows.
- How is the Paint Coverage Calculator calculated?
- Measure the room once and this works out the paintable wall area, takes off the doors and windows so you are not buying paint for glass, multiplies by the number of coats and divides by the coverage printed on the tin. Two coats is the honest default for a colour change. The maths is short enough to check by hand: Wall area = perimeter × height − openings. Paint needed = (wall area × coats) ÷ coverage per litre.
- Do I need to sign up, and is my data stored?
- No sign-up, and nothing you type is sent anywhere. The calculation runs in your own browser, so the figures stay on your device and the page works offline once loaded.
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Estimates for general guidance only. This is not financial, medical or legal advice. Everything runs in your browser and nothing you type is stored.