Paint Area Calculator
Calculate the exact amount of paint needed for a room by entering its dimensions, subtracting doors and windows, and accounting for coverage rate and number of coats.
Please enter valid values.
How to use
- Enter the room length, width and ceiling height in metres.
- Enter the number of doors and windows to subtract their area automatically.
- Enter the paint coverage (m² per litre from the tin) and number of coats, then click Calculate.
Frequently asked questions
What coverage rate should I use?
Coverage is printed on the paint tin — typically 10–12 m² per litre for standard emulsion. Rough or porous surfaces absorb more paint, so use the lower end of the range.
Does it include the ceiling?
No — this calculator covers the four walls only. For the ceiling, multiply length × width and divide by coverage to get the additional litres needed.
How many coats do I need?
Two coats are standard for most interior walls. Dark colours or bare plaster may need three. One coat is sometimes enough for touch-ups over the same colour.
Should I buy extra paint?
Yes — add 10% to the calculated amount for waste, touch-ups and future repairs. Paint tins come in fixed sizes, so round up to the nearest available size.