Enter Room length (ft), Room width (ft) and Wall height (ft) and the remaining scenario settings to review paint required with this tool. More coats increase the required amount; higher coverage per container reduces it.
Assumes 21 ft² per door and 15 ft² per window.
Paint required = Paintable area ÷ Coverage per unit × Number of coatsThe calculation links Room length (ft), Room width (ft) and Wall height (ft) to paint required. More coats increase the required amount; higher coverage per container reduces it. Openings only reduce area when they are included in the subtraction.
Enter Room length (ft), Room width (ft) and Wall height (ft) and the remaining scenario settings to review paint required with this tool. More coats increase the required amount; higher coverage per container reduces it.
Estimate paint from surface area, coat count and coverage. Separate the walls being coated from the container quantity that will be purchased.
More coats increase the required amount; higher coverage per container reduces it. Openings only reduce area when they are included in the subtraction.
Prepare Room length (ft), Room width (ft), Wall height (ft), Doors, Windows, Coats, Coverage per gallon (ft²) and Waste allowance (%). Measure paintable surfaces and verify product coverage for the intended coating and number of coats.
More coats increase the required amount; higher coverage per container reduces it. Openings only reduce area when they are included in the subtraction. Texture, color change, primer, application losses and manufacturer coverage can affect the purchase. A calculated fraction may require rounding up to a full container.
Use the full settings in the worked-example table. They produce Paint required: 1.9 gallons. Compare the method and units as well as the displayed number.
The displayed relationship is Paint required = Paintable area ÷ Coverage per unit × Number of coats Measure paintable surfaces and verify product coverage for the intended coating and number of coats.
Texture, color change, primer, application losses and manufacturer coverage can affect the purchase. A calculated fraction may require rounding up to a full container. Before ordering, compare the quantity with actual site measurements and the product coverage specification.
Worked paint calculator example. Set Room length (ft) = 12; Room width (ft) = 10; Wall height (ft) = 8; Doors = 1; Windows = 2; Coats = 2; Coverage per gallon (ft²) = 350; Waste allowance (%) = 10. The corresponding output is Paint required: 1.9 gallons. More coats increase the required amount; higher coverage per container reduces it.
Estimate paint from surface area, coat count and coverage. Separate the walls being coated from the container quantity that will be purchased.
Measure paintable surfaces and verify product coverage for the intended coating and number of coats.
| Field | Example value | Entry check |
|---|---|---|
| Room length (ft) | 12 | Enter the value for this scenario using the field label as the reference. |
| Room width (ft) | 10 | Enter the value for this scenario using the field label as the reference. |
| Wall height (ft) | 8 | Use the measurement unit printed beside this field and a consistent measuring technique. |
| Doors | 1 | Enter the value for this scenario using the field label as the reference. |
| Windows | 2 | Enter the value for this scenario using the field label as the reference. |
| Coats | 2 | Enter the value for this scenario using the field label as the reference. |
| Coverage per gallon (ft²) | 350 | Enter the value for this scenario using the field label as the reference. |
| Waste allowance (%) | 10 | Enter a percentage in the form requested by the field, keeping its stated time basis. |
Relationship used for this example: Paint required = Paintable area ÷ Coverage per unit × Number of coats
More coats increase the required amount; higher coverage per container reduces it. Openings only reduce area when they are included in the subtraction.
| Output | Displayed result |
|---|---|
| Paint required | 1.9 gallons |
With these settings, paint required is 1.9 gallons. Use the same units and calculation mode when reproducing this example.
More coats increase the required amount; higher coverage per container reduces it. Openings only reduce area when they are included in the subtraction. Texture, color change, primer, application losses and manufacturer coverage can affect the purchase. A calculated fraction may require rounding up to a full container.
Replace the illustrative room length (ft) value (12) with your own value, then complete the other inputs for the same scenario. Measure paintable surfaces and verify product coverage for the intended coating and number of coats.