Tool
Paint Calculator
Enter your room dimensions and how many coats you're painting. I'll figure out the wall area and how many gallons to buy.
0
gallons to buy
0 ft²
0 gal exact
How it's calculated
- Wall area = 2 × (length + width) × ceiling height.
- Subtract about 10% for doors and windows (optional).
- Gallons = area × coats ÷ coverage, rounded up to whole cans.
One gallon usually covers ~350 ft². Rough or porous walls drink more — check the can.
Related: Flooring & tile calculator →