Paint Calculator
Estimate the amount of paint required for a room, considering walls, doors, windows, and number of coats.
Enter values and click Calculate
Calculate How Many Litres of Paint You Need to Cover a Room
The Paint Calculator computes the paintable area by subtracting doors and windows from total wall area, then multiplies by the number of coats and divides by coverage per litre. It also recommends rounding up to the nearest litre for purchase.
Formula
Paint (L) = (Area - Openings) × Coats ÷ Coverage
How to Use?
- Enter total wall area (including all walls).
- Subtract area of doors and windows.
- Enter number of coats and coverage per litre (usually 10 m²/L).
- View litres needed and recommended to buy (rounded up).
Worked Examples
Example
Given:inputs
wallArea:50
doorsWindows:5
coats:2
coveragePerLitre:10
Result:calculated
paintableArea:45
litresNeeded:9
litresRounded:9
Measuring Walls
Measure each wall (width × height) and sum. Subtract doors/windows (standard door ~2 m², window ~1.5 m²).
Buying Paint
Always round up to the nearest litre to avoid shortages.
Table: Typical Paint Coverage
| Surface | Coverage (m²/L) |
|---|---|
| Smooth wall | 10-12 |
| Textured wall | 8-10 |
| Primer | 10-12 |
FAQs
What if my walls are not rectangular?
Estimate the area by approximating to rectangles or use a digital measuring tool.
Should I include ceilings?
If painting the ceiling, add its area separately.