How to use the Paint Calculator

Estimate paint gallons for walls or ceilings with multiple coats and coverage rate.

Calculation formula

Gallons required = area × coats ÷ coverage × (1 + waste%). Round up to whole-gallon equivalents.

Recommended steps

1. Enter values using the units shown beside each field.
2. Review whether the example assumptions match your situation.
3. Run the calculator and compare the key metrics.
4. Use the source data or official rates when precision matters.

Known limitations

Coverage depends on paint and substrate; primer and textured surfaces may change consumption.