Paint calculator: wall area, litres and cost
How much paint do walls and ceilings need?
Multiply paintable area by coats and divide by product coverage. For 40 m² of wall, two coats and 10 m²/l, you need 8 litres before waste: three 3-litre cans.
Wall area is twice the sum of length and width, times height, minus the total opening area. Ceiling area is length times width. For each paint, divide area times coats by coverage, add waste and round cans up separately. Primer covers all selected surfaces once.
Worked example
Walls are on. Ceiling and primer are off.
- Room length: 5 m
- Room width: 4 m
- Room height: 2.5 m
- Door and window area: 5 m²
- Wall coats: 2
- Wall paint coverage: 10 m²/l
- Wall paint can size: 3 l
- Price per wall paint can: 300 SEK
- Waste allowance: 0 %
- Labour cost: 100 SEK
- Delivery: 50 SEK
Wall area after openings: 40 m²; Wall paint with waste: 8 l; Wall paint cans: 3; Material cost: 900 SEK; Total cost: 1050 SEK.
Enter your own prices in SEK; example prices are not market prices. Labour and delivery are added separately. No tax relief is deducted.
How many litres of paint are needed per square metre?
Assuming 10 m²/l, each square metre uses 0.1 litres per coat. Two coats use 0.2 litres per m² before waste. This is an example, not universal coverage. Wall area deducts doors and windows. Ceiling paint and primer are calculated separately so different products and can sizes are not combined.
Assumptions and limitations
Use your product’s coverage and the coats needed for your surface. Wall, ceiling and primer cans are separate products and are not combined. Enabling primer assumes it is needed on all selected surfaces. The example contains assumptions, not a paint recommendation.
Product information
What would you like to calculate next?
Combine painting with other finishes in room renovation. If you are considering wallpaper, compare purchase quantities with the wallpaper calculator.