Paint Calculator
Estimate how much paint a room needs: gallons by wall area, coats and windows. Free paint coverage calculator.
Frequently asked questions
- How accurate is 350 sq ft per gallon?
- It is the label average for smooth interior walls. Rough, textured or unpainted surfaces can drop to 250–300.
- Should I buy gallons or quarts?
- Round up to whole gallons for large rooms — two partial gallons cost more than one full one. Keep a little for touch-ups.
- Do I need primer?
- Yes over new drywall, patched areas, stains or when switching from dark to light. Primer counts as a coat.
This tool runs entirely in your browser. No data is uploaded anywhere.