How much paint do I need for a 12x12 room?
About 2 gallons for two coats
The short answer
A 12 × 12 ft room with 8 ft ceilings has about 348 ft² of wall to paint once a standard door and window are taken out. Two coats cover 696 ft², and at roughly 375 ft² per gallon that is 1.9 gallons, so buy 2. The ceiling is extra: about 0.8 gallons of ceiling paint for two coats.
How it is worked out
- Perimeter: 2 × (12 + 12) = 48 ft
- Wall area: 48 ft × 8 ft = 384 ft²
- Take away one door (21 ft²) and one window (15 ft²): 348 ft²
- Two coats: 348 × 2 = 696 ft²
- Divide by 375 ft² per gallon: 1.9 → buy 2 gallons
Other sizes and options
| Ceiling height | Wall area | 1 coat | 2 coats | 3 coats |
|---|---|---|---|---|
| 8 ft | 348 ft² | 0.9 gal | 1.9 gal | 2.8 gal |
| 9 ft | 396 ft² | 1.1 gal | 2.1 gal | 3.2 gal |
| 10 ft | 444 ft² | 1.2 gal | 2.4 gal | 3.6 gal |
What can change the amount?
Use three coats when a light colour goes over a dark one, and add a primer on new plaster or bare wood. Rough or textured walls use more paint, so check the coverage printed on your can and round up.
Check each wall of your roomRoomveil opens with these measurements filled in. Change them to match your room, see the result on a photo, and get the exact amount. Free, no sign-up.Open in Roomveil
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.