How to estimate paint
Measure the room and choose coats.
1
Measure the perimeter
Add the lengths of all walls you will paint.
2
Subtract openings
Remove doors and windows from the wall area.
3
Choose coats
Two coats are standard for a colour change.
What does this tool do?
Paint coverage depends on the surface, colour change and number of coats. This calculator uses wall area minus openings and a coverage rate per litre, then adds a small margin for touch-ups.
The Formula
Litres = (Wall area − Openings) × Coats ÷ Coverage per litreFrequently Asked Questions
How much wall area does 5 litres cover?
At 10 m² per litre and one coat, 5 L covers about 50 m². Two coats halve the wall area covered.
Should I subtract doors and windows?
Yes for a more accurate estimate. Subtract the full opening area; most painters do not paint the frame with wall paint.