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Paint Calculator
Estimate how much paint you may need for walls based on area, coats, coverage, and waste allowance.
Enter your dimensions
Current unit: feet. The estimate updates automatically in your browser.
Enter the total wall area to paint.
Enter how many coats of paint you plan to apply.
Use the coverage value from the paint label for the selected unit system.
Optional. Add extra paint allowance as a percentage.
Estimated result
Paint needed
Enter your inputs
Your estimate will appear here automatically once the required inputs are valid.
Guide
How to use this estimate
How the paint calculator works
This calculator estimates paint quantity from wall area, number of coats, paint coverage, and optional waste allowance. In imperial mode, enter wall area in square feet and coverage in square feet per US gallon. In metric mode, enter wall area in square meters and coverage in square meters per liter.
The selected unit system controls the primary result. Imperial mode shows gallons first and liters as the equivalent value. Metric mode shows liters first and gallons as the equivalent value. Actual paint use can change based on wall texture, primer, color change, application method, and the paint brand's coverage rating.
What to measure
Enter the wall area you want to paint. If you do not already know it, use the Wall Area Calculator first.
Enter the number of coats and the coverage value from the paint label. Use square feet per US gallon in imperial mode, or square meters per liter in metric mode.
Example paint calculation
- Wall area: 360 square feet
- Coats: 2
- Coverage: 350 square feet per US gallon
- Waste allowance: 10%
- Paint estimate: (360 × 2 ÷ 350) × 1.10
Estimated paint needed: 2.26 gallons, equivalent to 8.57 liters.
Quick reference
| Item | Value | Note |
|---|---|---|
| Imperial coverage | Square feet per US gallon | Use this when the calculator is set to Imperial. |
| Metric coverage | Square meters per liter | Use this when the calculator is set to Metric. |
| Waste allowance | 0% to 15% | Higher waste can help with rough walls or touch-ups. |
Common mistakes to avoid
- Entering floor area instead of wall area.
- Mixing square feet per gallon with metric mode, or square meters per liter with imperial mode.
- Forgetting extra coats when covering a dark color with a light color.
Frequently asked questions
Should I use gallons or liters?
Use the unit system selected at the top of the calculator. Imperial mode uses square feet per US gallon and shows gallons first. Metric mode uses square meters per liter and shows liters first. The equivalent unit is also shown in the result.
Where do I find paint coverage?
Paint coverage is usually printed on the paint can or product listing. It may vary by brand, wall surface, and application method.
Should I include primer?
No. This calculator estimates paint quantity only. Primer coverage should be calculated separately if your project needs primer.