Paint Calculator
Estimate how many gallons of paint you need from wall area and coats.
Buying too little paint means a mismatched second trip to the store; buying too much wastes money. This estimates gallons needed from wall dimensions, coats, and your paint's coverage rate.
Why coverage rate varies by paint and surface
A gallon typically covers 300-400 square feet per coat, but this varies by brand, sheen, and surface texture — check the figure printed on your specific paint can.
Frequently asked questions
Should I subtract doors and windows from my wall area?
For large openings, yes — though many people skip this for a small buffer margin.
Do I need the same amount of paint for a second coat?
Usually slightly less, since it's covering an already-primed surface.