How much paint do I need for a 10x12 room?
About 2 gallons for two coats
The short answer
A 10 × 12 ft room with 8 ft ceilings has about 316 ft² of wall to paint once a standard door and window are taken out. Two coats cover 632 ft², and at roughly 375 ft² per gallon that is 1.7 gallons, so buy 2. The ceiling is extra: about 0.6 gallons of ceiling paint for two coats.
How it is worked out
- Perimeter: 2 × (10 + 12) = 44 ft
- Wall area: 44 ft × 8 ft = 352 ft²
- Take away one door (21 ft²) and one window (15 ft²): 316 ft²
- Two coats: 316 × 2 = 632 ft²
- Divide by 375 ft² per gallon: 1.7 → buy 2 gallons
Other sizes and options
| Ceiling height | Wall area | 1 coat | 2 coats | 3 coats |
|---|---|---|---|---|
| 8 ft | 316 ft² | 0.8 gal | 1.7 gal | 2.5 gal |
| 9 ft | 360 ft² | 1 gal | 1.9 gal | 2.9 gal |
| 10 ft | 404 ft² | 1.1 gal | 2.2 gal | 3.2 gal |
What can change the amount?
Use three coats when a light color goes over a dark one, and a primer on new drywall, bare wood or a big color change. Most US interior paints state 350 to 400 ft² per gallon; rough or textured walls use more, so check your can and round up.
Worked out with common rules of thumb and code minimums, for planning. Check the product label, the maker's instructions and your local building code before you buy or build. More detail in the Paint calculator guide.