Paint Calculator
Estimate gallons of paint from paintable area, number of coats, product coverage and a small waste allowance.
Paint details
Estimate
Use the actual product's stated coverage whenever possible. Surface texture, porosity, color change and application method can affect real coverage.
How paint quantity is estimated
Multiply the paintable area by the number of coats, add the selected waste allowance, then divide by the paint's coverage per gallon.
Worked example
Why coverage varies
Fresh drywall, rough masonry, deep color changes and porous surfaces can use more paint than a smooth, previously painted wall. Primer can also change the amount of finish paint required.
Paint calculator FAQ
Should I include doors and windows in the paintable area?
Enter the area you actually plan to paint. If openings are not being painted, subtract them before entering the total.
Does the calculator include primer?
No. Primer should be estimated separately because its coverage and coat requirements may differ from the finish paint.
Why round gallons up?
Paint is commonly purchased in fixed container sizes. The calculator rounds to whole gallons for a simple purchase estimate.