Estimate how much paint you need for walls and ceilings, account for doors and windows, choose the number of coats, and convert the result between gallons and litres.
Enter room dimensions in your chosen unit system. Add additional rooms or spaces when needed.
Rooms / spaces
There is no universal coverage number for every paint. Sherwin-Williams says a gallon typically covers about 350–400 square feet, but surface texture, application method and the product itself can change requirements.
Sherwin-Williams says a gallon of paint typically covers about 350–400 square feet, but product, surface condition and application method can change the actual amount needed. Check the product label or technical data for the paint you are using.
Yes. This is an independent paint estimator, not an official Sherwin-Williams calculator. Select the coverage unit and enter the coverage value printed on the exact Sherwin-Williams product label or technical data sheet. Do not assume every paint in a brand has the same coverage; finish, product line, surface and application method can change the amount needed.
Enter the paintable wall and ceiling area through the room dimensions, subtract significant doors and windows, then multiply by the number of coats. Divide the coat-adjusted area by the product's stated coverage per gallon or litre, and add any planning overage. The calculator combines multiple rooms into one estimate.
Yes. Deducting significant openings gives a closer estimate of the actual paintable surface. Small openings and trim can be handled differently depending on the project.
As a planning calculation, two coats are treated as twice the coated area. Actual product requirements can differ because hiding, substrate condition and application technique affect coverage.
A modest planning allowance can help with touch-ups and measurement uncertainty, but the appropriate amount depends on the project. Product-specific guidance should take priority.
Yes. The calculator supports metric dimensions and litre-based coverage as well as imperial dimensions and square-feet-per-gallon coverage.