🎨 Paint Calculator
Calculate exactly how much paint you need for walls, ceilings, and trim. No more running out mid-project or wasting money on extra gallons!
Calculate exactly how much paint you need for walls, ceilings, and trim. No more running out mid-project or wasting money on extra gallons!
?? Tip: Always buy 10% extra for touch-ups and waste.
Enter dimensions for each wall you want to paint.
Understanding paint coverage helps you buy the right amount. Coverage varies based on paint quality, surface texture, and application method.
| Surface Type | Coverage per Gallon | Notes |
|---|---|---|
| Smooth drywall | 400 sq ft | Best coverage, new construction |
| Textured drywall | 300-350 sq ft | Texture absorbs more paint |
| Bare wood | 250-300 sq ft | Requires primer first |
| Previously painted | 350-400 sq ft | Good coverage if well-prepped |
| Stucco | 150-200 sq ft | Very porous surface |
| Brick | 100-150 sq ft | Highly absorbent |
| Concrete | 200-250 sq ft | Use masonry paint |
Premium paint covers better, lasts longer, and often requires fewer coats. The extra cost pays off in coverage and durability.
Clean walls, fill holes, sand rough spots, and use painter's tape. Good prep makes for a professional finish.
Paint between 50-85×F with humidity under 70%. Don't paint in direct sunlight or if rain is expected.
Even if one coat looks good, two coats ensure durability, even coverage, and true color depth.
Wait 2-4 hours between latex coats, 24 hours for oil-based. Rushing causes peeling and poor adhesion.
Always buy 10-15% more paint than calculated. Same batch ensures color consistency for touch-ups.
Paint coverage varies by surface texture, paint quality, and application method. These standards come from major paint manufacturers (Sherwin-Williams, Benjamin Moore, Behr) and represent typical conditions:
| Paint Type / Quality | Coverage per Gallon | Price per Gallon (2026) | Best Application |
|---|---|---|---|
| Budget interior latex | 350×400 sq ft | $20×35 | Rentals, single use |
| Mid-grade interior (Behr, PPG) | 400×450 sq ft | $35×55 | Most interior walls |
| Premium interior (SW Emerald, BM Aura) | 400×450 sq ft | $65×90 | 1-coat coverage, durability |
| Exterior (acrylic latex) | 300×400 sq ft | $40×70 | Siding, trim |
| Primer (interior) | 300×400 sq ft | $25×45 | New drywall, dark colors |
| Ceiling paint | 400×450 sq ft | $25×45 | Flat finish, spatter resistant |
Estimate paint needs (1 gallon ≈ 350 sq ft per coat).
A room with 400 square feet of wall area, painted with two coats.
Result: 400 × 2 ÷ 350 = 2.3 → buy 3 gallons.
A single accent wall of 120 sq ft, two coats.
Result: 120 × 2 ÷ 350 = 0.69 → 1 gallon is plenty.
A large room with 1,000 sq ft of total wall area.
Result: 1,000 × 2 ÷ 350 = 5.7 → buy 6 gallons.
Divide total wall area by ~350 sq ft per gallon, then multiply by the number of coats.
Usually two for even coverage, more when changing colors dramatically.
Multiply wall length by height, sum the walls, then subtract large doors and windows.
Quick unit conversions related to this calculator: