Paint Calculator
Work out how much paint you need for a room. Enter the room size, doors, windows and number of coats, plus the coverage printed on your tin.
- Area to paint
- 32.9 m²
- Paint needed
- 4.7 litres
- Tins to buy
- 2 × 4 L, or 1 × 10 L
Need someone to do the job? Find painters & decorators near you and contact them directly, with no lead fees.
How it works
- Wall area = 2 × (length + width) × height, minus 1.6 m² for each door and 1.5 m² for each window. Tick the ceiling to add length × width.
- Litres = area × coats ÷ coverage. Tins are rounded up, so you will usually have a little left for touch-ups.
These are estimates for planning and comparing quotes, not a substitute for a professional's measurements.
Common questions
How far does a litre of paint go?
Most interior wall paints cover about 12 to 16 m² per litre per coat on smooth, sealed walls. Rough, porous or bare surfaces take more, so use the figure on the tin.
How many coats of paint do I need?
Two coats is standard for walls. You may need a primer or sealer first on new plasterboard, bare timber, or when making a big colour change.
What about exterior walls?
Use the same method with the wall area of each side, minus doors and windows. Exterior surfaces such as weatherboards often use more paint than the tin's figure, so add extra.