Paint Coverage Calculator
Calculate gallons of paint needed for any room.
Enter wall area, coats, and surface type to get gallons required and total project cost estimate.
Paint Gallons Needed
Paint Coverage Estimation
Paint coverage depends on paint type, surface, and coat count.
Standard coverage (smooth drywall, primed):
| Paint Type | Coverage per Gallon |
|---|---|
| Latex flat / matte | 350-400 sq ft |
| Latex eggshell / satin | 350-400 sq ft |
| Latex semi-gloss / gloss | 300-350 sq ft |
| Oil-based paint | 300-350 sq ft |
| Primer | 200-300 sq ft |
| Stain (deck/fence) | 150-250 sq ft |
| Concrete / masonry | 75-150 sq ft |
Surface adjustments:
- Smooth / new drywall: 1.0× coverage rate
- Lightly textured drywall: 0.9× (10% more paint)
- Heavily textured / orange peel: 0.75-0.8× (25% more paint)
- Stucco / popcorn: 0.6× (40-65% more paint)
- Brick / masonry: 0.5× (50% more paint)
- Raw / unprimed wood: 0.7× (30% more paint)
Number of coats:
- Same color, same brand: 1 coat usually fine
- Same color over light to medium tint: 2 coats recommended
- Light over dark: 2-3 coats + primer
- Dark over light: 1-2 coats with quality paint
- Bright / saturated colors (red, yellow): 3+ coats often needed
Calculation: Gallons = (Total area × Coats) / (Coverage per gallon × Surface factor)
Standard room measurements:
- 12×12 ft room with 8 ft ceilings: ~384 sq ft of wall surface (minus doors/windows)
- 12×16 ft room: ~448 sq ft
- 14×20 ft room: ~544 sq ft
Subtract for openings:
- Standard interior door: ~21 sq ft
- 36×60 in window: ~15 sq ft
- 36×72 in window: ~18 sq ft
Exterior considerations:
- Add 10% for waste, drips, brush rinses
- Add 20-30% for first-coat primer on raw siding
- Plan two coats for fade-prone exposures (south, west)
Cost ranges (US, 2026):
- Builder-grade interior latex: $20-30/gallon
- Mid-range (Behr, Sherwin-Williams ProMar): $35-50/gallon
- Premium (Benjamin Moore Aura, SW Emerald): $60-90/gallon
- Specialty (chalkboard, magnetic, fire-rated): $40-100/gallon