Paint Quantity CalculatorFree online other calculator — instant results, no sign-up
Estimate paint from net paintable area, coats and labeled coverage.
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About the Paint Quantity Calculator
The Paint Quantity Calculator estimates the liters of paint needed from net wall area, the number of coats, and the paint’s labeled coverage. With the default inputs of 80 m², 2 coats, and 10 m²/L, the estimated requirement is 16 L.
- Net wall area (m²)
- The wall surface to be painted, after subtracting unpainted openings such as doors and windows, measured in square meters (default: 80 m²).
- Coats
- The number of paint layers to apply over the entire net wall area, entered as a unitless count (default: 2).
- Coverage (m²/L)
- The area one liter of paint is expected to cover in one coat, measured in square meters per liter using the product label (default: 10 m²/L).
Formula and method
V = (A × N) / C; with the default inputs, V = (80 m² × 2) / (10 m²/L) = 16 L.
- VEstimated paint quantity in liters (L).
- ANet wall area in square meters (m²).
- NNumber of coats applied to the full net wall area.
- CPaint coverage per coat in square meters per liter (m²/L).
Multiply the net wall area by the number of coats to obtain the total area to cover across all coats, then divide by the labeled coverage. For the default inputs, 80 × 2 = 160 m² of coat-area, and 160 ÷ 10 = 16 L. Coverage must be greater than zero.
Worked example
These are the calculator's starting values and the results it actually produces for them.
Inputs
- Net wall area80 m²
- Coats2
- Coverage10 m²/L
Results
- Result16 L
How to use the Paint Quantity Calculator
- 1Measure the walls and subtract doors, windows, and any other surfaces that will not be painted to obtain the net wall area.
- 2Enter the net wall area in m²; the default is 80.
- 3Enter the number of coats planned for the full area; the default is 2.
- 4Enter the paint’s labeled coverage per coat in m²/L; the default is 10.
- 5Read the estimated paint quantity in liters, then account separately for application losses and available container sizes before purchasing.
Reading your result
The Result row gives the estimated total paint volume for all specified coats, in liters. With the default inputs, 16 L means the calculated amount needed to cover 80 m² twice at 10 m²/L per coat. It is not a per-coat amount and does not include an added waste allowance or rounding to container sizes.
Limitations
The estimate assumes every coat covers the same net area at the entered coverage rate. Actual consumption can vary with surface texture, porosity, application technique, equipment losses, and color changes. Primer, trim, ceilings, and other surfaces are excluded unless separately accounted for. The calculator does not determine how many coats a particular paint or surface requires, add a contingency allowance, or choose container sizes.
Common questions
Should I subtract doors and windows from the wall area?+
Yes, subtract openings and any other areas you will not paint. If doors or trim also need painting, estimate them separately using their own paint coverage and coat requirements.
Does the 16 L default result include both coats?+
Yes. The calculation multiplies 80 m² by 2 coats before dividing by 10 m²/L, so 16 L is the total for both coats.
What if the paint label gives a coverage range?+
Use a coverage value appropriate to the surface and the manufacturer’s guidance. Choosing the lower end of the labeled range produces a larger, more conservative paint estimate; rough or porous surfaces may need more paint than smooth, sealed walls.
Does this estimate include primer or extra paint for touch-ups?+
No. Estimate primer separately using its own labeled coverage and required coats. Add any allowance for waste and future touch-ups separately, then round the purchase quantity up to suitable container sizes.
Does the calculator save my information?+
Calculations run in your browser. While signed in, inputs and results are automatically recorded in account history; saving a result creates a separate saved record.
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Results are estimates for informational purposes and are not financial, medical or legal advice.