Paint Calculator
Calculate how much paint you need (litres or gallons) for walls and ceilings based on room size, number of coats, and openings.
Results
How to Calculate Paint
Multiply the room perimeter by ceiling height for total wall area. Subtract roughly 2 m² (21 sq ft) per door and 1.4 m² (15 sq ft) per window. Divide by your paint's coverage rate (typically 10-12 m² per litre, or 350 sq ft per US gallon) and multiply by number of coats.
Frequently Asked Questions
How much paint do I need for a room?
A typical 3.6 x 3.6 m (12 x 12 ft) room with 2.4 m (8 ft) ceilings has about 36 m² (384 sq ft) of wall area. After subtracting doors and windows, you need roughly 5-6 litres (1.5 US gallons) for two coats.
How many coats of paint do I need?
Two coats is standard for a colour change. One coat may be enough if recoating the same colour over a well-primed surface. Use primer plus two coats over new plasterboard/drywall or dark colours.