Work out how much paint you need for a room. Enter the room size, the number of doors and windows and the number of coats, and this free calculator estimates the amount in litres or US gallons.
| Wall area to paint | – |
| Area of doors and windows removed | – |
| Total area including coats | – |
How it works
Wall area = 2 × (length + width) × height. The calculator subtracts about 1.8 m² (20 sq ft) for each door and 1.2 m² (15 sq ft) for each window, adds the ceiling if you choose, multiplies by the number of coats and divides by the coverage of the paint. Coverage is printed on the tin and varies by brand, colour and surface.
Buy a little extra for touch-ups, and remember that dark colours, rough walls and bare plaster need more paint.
Example
A 5 m by 4 m room with 2.5 m walls, one door, two windows and two coats needs about 8.2 litres at 10 m² per litre.
Frequently asked questions
How much paint do I need for a 12 by 12 foot room?
With 8-foot walls, two coats and typical coverage, roughly one to one and a half gallons. Use the calculator with your own numbers.
Do I include the ceiling?
Only if you are painting it. Ceiling paint is often a different product.
Should I buy extra?
Many people add 5 to 10 percent for touch-ups and uneven surfaces.
More free tools: Area calculator · Tile calculator · All free tools
Estimates only. Always check product instructions and add a safety margin before you buy materials.