Paint Calculator
Calculate how many litres of paint you need for a room based on wall dimensions, coats, and coverage rate.
Paint needed
8.4 L
Total wall area
45 m²
Paintable area
42 m²
Enter your room's length, width, and height along with the number of coats and your paint's coverage rate to estimate exactly how much paint to buy. Subtract the area of doors and windows for a more accurate result. Everything is computed instantly in your browser.
How to use
- Enter the room's length, width, and height in meters.
- Set the number of coats and your paint's coverage rate per litre.
- Subtract the area of doors/windows to get the litres of paint needed.
Frequently asked questions
- How is wall area calculated?
- Wall area = perimeter (2 × (length + width)) × height, minus any area you subtract for doors and windows.
- What coverage rate should I use?
- Check your paint can label; most paints cover 8–12 m² per litre, but this varies by brand and surface.
- Why does it multiply by the number of coats?
- Each coat requires the full paintable area's worth of paint, so total litres scale directly with the number of coats.