Room Paint Calculator
Estimate how much paint you need for the walls of a room. Enter the room size, ceiling height, the area of doors and windows and the number of coats.
8 of 8 free uses remaining today
Estimate how much paint you need for the walls of a room. Enter the room size, ceiling height, the area of doors and windows and the number of coats.
Worked example
Example calculated from the starting values. Enter your own values and press Calculate to get your result.
With the default inputs (room length = 4 m, room width = 3.5 m, ceiling height = 2.4 m, doors and windows = 3 m², coats = 2), the results are: wall area 33.00 m²; paint needed (12 m² per litre) 5.5 L.
Quick reference: room length vs result
Reference table based on the example values; it is not your calculation result.
| Room length (m) | Wall area | Paint needed (12 m² per litre) |
|---|---|---|
| 2 | 23.40 m² | 3.9 L |
| 4 | 33.00 m² | 5.5 L |
| 8 | 52.20 m² | 8.7 L |
| 20 | 109.80 m² | 18.3 L |
| 40 | 205.80 m² | 34.3 L |
| 80 | 397.80 m² | 66.3 L |
Frequently asked questions
What formula does this calculator use?
Wall area = 2 × (l+w) × h-open; Paint needed (12 m² per litre) = wa × coats ÷ 12. Variables: l = room length in m, w = room width in m, h = ceiling height in m, open = doors and windows in m², coats = coats.
What do I need to enter?
You need room length (m), room width (m), ceiling height (m), doors and windows (m²), coats. Results update as you type.
What is an example result?
With the default inputs (room length = 4 m, room width = 3.5 m, ceiling height = 2.4 m, doors and windows = 3 m², coats = 2), the results are: wall area 33.00 m²; paint needed (12 m² per litre) 5.5 L.
Related Tools
View allPaint Calculator by Area
Work out how much paint you need for a floor, wall or surface. Enter the length and width, the number of coats and a waste allowance. Based on…
Primer Calculator by Area
Work out how much primer you need for a floor, wall or surface. Enter the length and width, the number of coats and a waste allowance. Based on…
Floor sealer Calculator by Area
Work out how much floor sealer you need for a floor, wall or surface. Enter the length and width, the number of coats and a waste allowance. Based…
Wood stain Calculator by Area
Work out how much wood stain you need for a floor, wall or surface. Enter the length and width, the number of coats and a waste allowance. Based on…