Paint Calculator
Estimate how many liters of paint you need for walls and ceilings.
Assumptions
1 liter covers approximately 10-12 m² per coat. Two coats recommended for best finish.
Paint Required
How to use the Paint Calculator
- Enter the room length, width and wall height in metres.
- Enter the number of doors and windows.
- Click Calculate to see the paintable area and litres needed for two coats.
- Round up to the can sizes available (1 L, 4 L, 10 L, 20 L).
Formula used
Litres = area × 2 coats ÷ 10 m² per litre
The calculator includes the ceiling and assumes a coverage of 10 m² per litre per coat.
Worked example
Room 4 m × 3 m, 3 m high, 1 door, 2 windows
Walls 42 m² + ceiling 12 m² − door 2 m² − windows 3 m² = 49 m²
Paint for two coats = 49 × 2 ÷ 10 ≈ 10 litres (3 cans of 4 L)
Primer, putty and coverage
New plaster or a big colour change needs a coat of primer first, and uneven walls need wall putty. Actual coverage depends on the paint and surface: premium emulsions often cover 12–16 m² per litre per coat on smooth walls, while textured or porous walls take more. Check the coverage printed on the can and adjust.
Tips for accurate results
- Buy all paint for one room from the same batch for an even shade.
- Dark colours over light walls (or the reverse) may need a third coat.
- If you are not painting the ceiling, subtract L × W from the area.
Frequently Asked Questions
For a 10×10 ft room with 10 ft walls (about 3 m × 3 m × 3 m), roughly 8–9 litres for two coats including the ceiling.
Two coats are standard for an even finish.
No. Estimate primer separately using the same area.
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Content reviewed by Vinod, Easy Smart Calculator · Last updated October 2026