Loan Paint Coverage Calculator
Enter your room's dimensions, subtract doors and windows, and get exactly how many gallons of paint to buy — no more guessing at the store.
| Total wall area | 0 sq ft |
| Minus doors & windows | 0 sq ft |
| Paintable area (with coats) | 0 sq ft |
| Coverage rate used | 350 sq ft / gal |
How it works
Wall area is 2 × (length + width) × height, minus 21 sq ft per door and 15 sq ft per window, multiplied by the number of coats. At the standard coverage of 350 sq ft per gallon, the result is rounded up — you can't buy a partial gallon.
Frequently asked questions
How many square feet does a gallon of paint cover?
Most interior latex paints cover about 350 square feet per gallon per coat. Primer and cheap paints may cover less.
Should I paint one coat or two?
Two coats give even color, better durability, and truer coverage of the old color. One coat is fine for a refresh in the same color.
Do I need primer too?
On bare drywall, stains, or dramatic color changes — yes. Over existing paint in good shape, a quality paint-and-primer is usually enough.
🛠️ Planning a bigger project?
Estimate deck lumber with our deck material estimator, or compare paint prices per ounce with the unit price calculator.