Paint Calculator
Estimate paint litres and whole tins from your measured area and product coverage.
Planning more than one room or material? Build a project shopping list →
How to use it
- Replace the examples with your measurements or exact product coverage.
- Choose the unit beside each input. Changing the unit converts the existing value.
- Choose any allowance deliberately, calculate, and check the purchase units.
Formula
Litres = net area × coats ÷ coverage × (1 + extra/100). Tins = round up(litres ÷ tin volume).
Worked example
40 m² × 2 coats ÷ 10 m²/L × 1.1 = 8.8 L; buy two 5 L tins.
Common mistakes and limits
Enter coverage from the product label for one coat. Surface porosity and application affect usage. Fractional coats are rejected.
Do not add allowance twice. Example coverage, density and prices are illustrative, not a specification for your project.
Frequently asked questions
Should coverage describe one coat?
Yes. Enter the labelled per-coat spreading rate, then enter the number of coats separately.
Are US and imperial gallons equal?
No. The unit selector distinguishes them; choose the one used on the product information.
Are my measurements sent to a server?
These calculations run in your browser. This calculator does not send the input values to our server. Normal page requests can still appear in hosting logs.
Measurement guides
- Paintable wall area: subtract openings once
- Paint coverage, coats and tin size are three separate inputs
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