Interior Paint Calculator
Estimate wall paint for a room in gallons. The calculator figures wall area from your room size and ceiling height, deducts ~10% for doors and windows, and multiplies by coats.
Interior Paint calculator
ft
ft
ft
How to estimate interior paint
- One gallon covers about 350 sq ft per coat on smooth, primed walls; rough or new drywall drinks more.
- Two coats is standard. Plan a separate primer coat over new drywall or a big color change.
- Buy all wall paint in one tinted batch so the color is consistent across the room.
Frequently asked questions
How much paint do I need for a 12x12 room?
A 12x12 room with 8 ft ceilings has about 384 sq ft of wall. Two coats need roughly 2 gallons after a 10% deduction for openings.
How many square feet does a gallon of paint cover?
About 350 sq ft per coat on smooth, primed surfaces.