🎨 How much paint do I need?
A gallon of paint covers about 350–400 sq ft in one coat, so for the usual two coats a gallon does roughly 175–200 sq ft. A standard 12×12 room needs about 2 gallons for two coats. Enter your room below for the exact gallons and cost.
Room size
Based on the standard ~350–400 sq ft a gallon covers per coat (we use 375). Rough or porous walls, deep colour changes and sprayers all use more; a primer coat counts as a coat. We round up to whole cans to buy.
Paint by room size (2 coats)
| Room (8-ft ceiling) | Wall area | Gallons |
|---|---|---|
| 10 × 10 ft (bedroom) | 269 sq ft | 2 gal |
| 12 × 12 ft (bedroom) | 333 sq ft | 2 gal |
| 12 × 16 ft (living room) | 397 sq ft | 3 gal |
| 15 × 20 ft (great room) | 509 sq ft | 3 gal |
Walls only, two coats, minus one door and two windows, at ~375 sq ft per gallon per coat. Add a gallon for the ceiling or a big colour change. Rounded up to whole cans.
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Frequently asked
How much does a gallon of paint cover?▾
About 350 to 400 square feet in a single coat on a smooth, primed wall — most cans state 350–400 on the label. For the usual two coats, plan on one gallon covering roughly 175 to 200 square feet. Rough, porous or previously-unpainted surfaces soak up more and cut the coverage, and a big colour change often needs an extra coat.
How many square feet are in a gallon of paint?▾
A gallon covers about 350 to 400 square feet per coat — that is the standard coverage figure printed on most paint cans. Divide your paintable wall area by 350 to be safe, then multiply by the number of coats, to get the gallons you need. A quart covers about 90–100 square feet for touch-ups or a small accent.
How much paint do I need for a 12x12 room?▾
About 2 gallons for two coats. A 12×12 room with an 8-foot ceiling has roughly 333 square feet of wall after subtracting a door and two windows; two coats is about 1.8 gallons of coverage, so you buy 2. Add a gallon if you're also painting the ceiling or making a big colour change.
How much paint do I need to paint a house interior?▾
For a whole interior, add up the wall area room by room (perimeter × ceiling height, minus doors and windows) and divide by 350, times two coats. As a rough rule of thumb, a 2,000 sq ft home interior takes on the order of 12 to 16 gallons for walls in two coats, plus trim and ceilings. The calculator above does it one room at a time.