How to work out how much paint you need
- Choose Feet or Metres and enter the room’s length, width and wall height.
- Enter the number of Doors and Windows, the Coats you’ll apply and the Coverage printed on the paint can. Tick the ceiling if you’re painting it the same paint.
- Read how much paint you need and which cans or tins to buy.
How the paint is worked out
- Wall area = 2 × (length + width) × height.
- Take off the doors and windows.
- Add the ceiling (length × width) if you’re painting it.
- Paint = area × coats ÷ coverage.
The calculator rounds up to whole cans: quarts and gallons in feet, or 5 L, 2.5 L and 1 L tins in metres, choosing the mix that wastes least. Buying a slightly larger can is often cheaper than two small ones, and leftover paint is handy for touch-ups.
Tips for an accurate amount
- Use the coverage on your can. Thick, cheap or very dark paints can cover less than the label’s best case.
- Trim and doors use different paint. Skirting boards, door frames and the doors themselves are usually painted in a gloss or satin; a quart or a 750 ml tin covers most rooms.
- Measure each room. For a whole house, work out each room separately and add them up.
Decorating rather than painting? The wallpaper calculator works out rolls for the same room.