Estimate how much paint you need for a given wall area and number of coats.
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How do you calculate how much paint you need?
Paint needed = area × coats ÷ coverage, with typical coverage about 350 ft² per gallon or 11 m² per litre. For example, a 400 ft² wall with 2 coats at 350 ft²/gallon needs about 2.5 gallons. Subtract doors and large windows from the area for a closer estimate, and buy a little extra for touch-ups.
Understanding your result
Subtract doors and large windows from the area for a closer estimate, and buy a little extra for touch-ups.
Formula and method
Paint needed = area × coats ÷ coverage. Typical coverage is about 350 ft² per gallon or 11 m² per litre.
Worked example
A 400 ft² wall with 2 coats at 350 ft²/gallon needs about 2.5 gallons.
How to use this tool
- Enter the wall area to paint.
- Set the number of coats and the coverage.
- Press Calculate.
About the Paint Calculator
The Paint Calculator estimates how much paint a job needs based on the wall area, the number of coats and the paint’s coverage.
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Frequently asked questions
How many coats do I need?
Two coats is typical for good coverage. Dark colours or big colour changes may need a primer plus two coats.