Paint Guide · 4 min read
How much paint for a room?
A standard 12x12 bedroom with 8 ft ceilings needs about 2 gallons of paint for two coats on the walls. Below is the full chart by room size, plus the math so you can calculate any room.
Paint needed by room size
Based on 8–9 ft ceilings, average number of doors and windows, and two coats of standard interior paint at 350 sq ft per gallon.
| Room size | Typical use | Paintable wall area | Gallons (2 coats) |
|---|---|---|---|
| 8 × 10 ft | Small bathroom | ~255 sq ft | 2 gallons |
| 10 × 10 ft | Small bedroom / office | ~285 sq ft | 2 gallons |
| 12 × 12 ft | Standard bedroom | ~335 sq ft | 2 gallons |
| 12 × 15 ft | Kitchen / dining | ~340 sq ft | 2 gallons |
| 15 × 15 ft | Master bedroom | ~475 sq ft | 3 gallons |
| 15 × 20 ft | Living room | ~545 sq ft | 4 gallons |
| 20 × 25 ft | Large living room | ~710 sq ft | 5 gallons |
Numbers assume walls only — not ceilings or trim. Subtract about 21 sq ft per door and 15 sq ft per window.
Want the exact number for your room? It takes 10 seconds.
Use the paint calculator →How much paint for a bedroom?
Most bedrooms are between 10x10 and 15x15. That's 2–3 gallons for two coats. A small guest room fits in 2 gallons. A master bedroom with vaulted ceilings or extra walls usually needs 3, sometimes 4. If you're going from a dark color to a light one, plan for three coats — and an extra gallon.
How much paint for a living room?
Living rooms are the most variable. A 15x20 room with 9 ft ceilings needs 4 gallons for two coats. Rooms 20x25 or bigger typically need 5. Open-plan great rooms can run 6–7 gallons. Measure the actual wall length — open-plan rooms trick the eye.
How much paint for a bathroom?
A standard 8x10 bathroom needs 2 gallons for two coats after subtracting the door and window. Buy mildew-resistant or bathroom-specific paint — regular flat paint peels in steam. You'll rarely need more than 2 gallons for a full bath, even with two coats of primer.
How much paint for a kitchen?
Kitchens are deceptive. Cabinets cover 30–40% of the wall area, so the actual paintable surface is smaller than you'd guess. A 12x15 kitchen usually takes 2 gallons for two coats on walls only. Painting the cabinets themselves is a separate project — you'll need about 1 gallon of cabinet-grade enamel for a standard kitchen of cabinet faces.
How much paint for a dining room?
A 12x14 dining room with two doorways and two windows needs 2 gallons for two coats. Most dining rooms fit in 2 gallons; larger formal rooms (14x18+) may need 3.
How to calculate it yourself
The formula is simple enough to do on the back of an envelope:
- Measure the perimeter. Add up the lengths of all four walls.
- Multiply by ceiling height. That's the total wall area in square feet.
- Subtract doors and windows. 21 sq ft per door, 15 sq ft per window.
- Multiply by number of coats. Usually two.
- Divide by 350. That's roughly how many square feet one gallon covers.
- Round up. Always. Running out mid-wall is worse than a leftover quart.
Example: A 12x12 room with 8 ft ceilings, 1 door, 2 windows, two coats. Perimeter 48 × 8 ft = 384 sq ft total wall. Minus 21 (door) and 30 (windows) = 333 sq ft paintable. × 2 coats = 666 sq ft. ÷ 350 = 1.9 gallons. Round up: 2 gallons.
Common mistakes people make
- Forgetting the second coat. Paint cans list coverage for one coat. Always plan for two unless you're painting the same color over the same color.
- Not subtracting openings. A door and two windows save you ~50 sq ft — that's 15% of a small room.
- Measuring the floor instead of the walls. You paint the walls, not the floor. Floor area has nothing to do with paint quantity.
- Assuming all paints cover the same. Cheap paint covers ~250 sq ft per gallon. Premium paint covers 400+. Check the can.
- Skipping primer on drywall. Bare drywall soaks up paint. Use primer first or you'll need an extra gallon.
FAQ
How much paint for a 12x12 room?
About 2 gallons for two coats, assuming 8 ft ceilings, one door, and two windows. Use the calculator for an exact number.
How much paint for a bedroom?
Most bedrooms need 2 gallons for two coats. A small bedroom (10x10) fits in 2 gallons; a master (15x15) typically needs 3.
How much paint for a living room?
A 15x20 living room with 9 ft ceilings needs about 4 gallons for two coats. Larger rooms (20x25 or bigger) usually need 5.
How much paint for a bathroom?
A standard 8x10 bathroom needs about 2 gallons for two coats after subtracting the door and window. Use mildew-resistant bathroom paint.
Should I buy an extra can?
Yes — buy a little extra and save it. Leftover paint from the same batch is the easiest way to fix scuffs and touch-ups years later. Batch numbers on the can are your friend.