How Much Paint Do I Need?
How much paint you need is your wall area divided by the coverage per gallon (about 350 square feet), times the number of coats. A 12 by 12 foot room with 8 foot walls has about 384 square feet of wall, needing about 2 gallons for two coats. The table below covers common room sizes, and the calculator works out your exact amount.
| Room size | Wall area | Gallons (2 coats) |
|---|---|---|
| 10 x 10 ft | 320 sq ft | 2 |
| 12 x 12 ft | 384 sq ft | 2.5 |
| 12 x 16 ft | 448 sq ft | 3 |
| 15 x 20 ft | 560 sq ft | 3.5 |
| 20 x 20 ft | 640 sq ft | 4 |
Get your exact number
Calculate your exact amount with the paint calculatorHow Do You Calculate Paint Needed?
To calculate paint, find the wall area by multiplying the room perimeter by the wall height, subtract doors and windows, then divide by 350 (the square feet one gallon covers) and multiply by the number of coats. A room with 384 square feet of wall needs about 1.1 gallons per coat, or about 2.5 gallons for two coats. The table assumes 8 foot walls and two coats; the calculator handles your exact room and coat count.
How Many Coats of Paint Do You Need?
Most jobs need two coats for even color and full coverage, especially over a different color or fresh drywall. One coat may do when repainting the same color over a sound surface, and three coats are sometimes needed for deep or bright colors over light, or covering dark with light. Primer is separate. The calculator lets you set the coat count; the table assumes the common two coats.
Frequently asked questions
- How much paint do I need for a 12x12 room?
- A 12 by 12 foot room with 8 foot walls has about 384 square feet of wall, needing about 2.5 gallons for two coats.
- How many square feet does a gallon of paint cover?
- About 350 square feet per gallon for one coat on a smooth, primed surface.
- How many coats of paint do I need?
- Usually two coats for even coverage. One coat may do over the same color; three for deep colors or covering dark with light.