Paint Calculator
Updated Formulas shown
A 12 × 12 ft room with 8 ft walls, one door and two windows needs about 1.9 gallons for two coats — two gallon cans.
Paint needed
2 gal
8 quarts · 2 coats
- Paintable area
- 333 ft²
- Exact gallons
- 1.9
- Primer (1 coat)
- 1.25 gal
Doors count as 21 ft², windows as 15 ft². Buy 1-gallon cans up to 3 gal, then a 5-gallon bucket.
Quick reference
| Room | Wall area | Gallons |
|---|---|---|
| 10 × 10 ft | 269 ft² | 1.75 |
| 10 × 12 ft | 301 ft² | 1.75 |
| 12 × 12 ft | 333 ft² | 2 |
| 12 × 14 ft | 365 ft² | 2.25 |
| 14 × 16 ft | 429 ft² | 2.5 |
| 16 × 20 ft | 525 ft² | 3 |
Related calculators
- Drywall CalculatorCalculate drywall sheets (4x8, 4x10, 4x12), screws, joint compound and tape for walls and ceilings.
- Wallpaper CalculatorCalculate rolls of wallpaper from total wall width, height and openings, accounting for pattern repeat.
- Square Footage CalculatorCalculate square footage of rectangles, circles, triangles and trapezoids, with square yards, square meters, acres and cost.
Frequently asked questions
How many square feet does a gallon of paint cover?
350–400 ft² per coat on smooth, primed walls; textured or porous surfaces can drop to 250 ft².
Your business here? Sponsor this calculator from $13/week. See placements
Estimates only. Check quantities with your supplier or contractor before ordering.