Paint calculator
One more coat. One fewer store trip.
Calculate paint volume and whole cans from net surface area, coats, and the coverage on your chosen paint label.
BEHIND THE NUMBERS
Clear math. Better decisions.
Paint volume = net surface area × coats ÷ coverage × allowance factor. Divide by can volume and round up.
A worked example
For 700 square feet, two coats, and a label coverage of 350 square feet per gallon, the baseline is 4 US gallons. A 10% allowance increases it to 4.4 gallons, so buy five one-gallon cans.
Before you order
- Measure paintable surface area, not the floor area of the room.
- Deduct unpainted doors or windows before entering net area. Add multiple walls together.
- Coverage varies with texture, porosity, color change, and product. Primer is a separate estimate.
Good questions.
Should I enter floor area?
No. Enter the actual area of the walls, ceiling, fence, or other surfaces being painted. For several walls, sum width times height and subtract any large unpainted openings.
Does this include primer?
No. Primer may have a different coverage rate and number of coats. Run a separate calculation using its own label values.