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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

  1. Perimeter: 2 × (10 + 12) = 44 ft
  2. Wall area: 44 ft × 8 ft = 352 ft²
  3. Take away one door (21 ft²) and one window (15 ft²): 316 ft²
  4. Two coats: 316 × 2 = 632 ft²
  5. Divide by 375 ft² per gallon: 1.7 → buy 2 gallons

Other sizes and options

Ceiling heightWall area1 coat2 coats3 coats
8 ft316 ft²0.8 gal1.7 gal2.5 gal
9 ft360 ft²1 gal1.9 gal2.9 gal
10 ft404 ft²1.1 gal2.2 gal3.2 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.

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