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Calculate paint gallons for walls and ceilings. Enter room dimensions, coats, and coverage rate to get primer and paint gallons with waste allowance.
Estimate spray paint cans for projects from surface area and coverage. Calculate primer, color coats, and clear coat cans for metal, furniture, and crafts.
Estimate primer gallons from surface area and substrate type. Calculate stain-blocking, drywall, and masonry primer for proper paint prep coverage rates.
Include treads, risers, and railing square footage. Grooved boards absorb more product — reduce coverage 20%.
Area = Length × Width + Stairs + Rail LF × Height factorNew smooth cedar: 250–300 sq ft/gal. Weathered porous wood: 150–200 sq ft/gal. Two thin coats better than one heavy.
Gallons = Area ÷ Coverage (150–300 sq ft/gal)Solid stain covers like paint (~200 sq ft/gal). Penetrating oil semi-transparent spreads farther on tight grain.
Solid hides more — lower sq ft/gal; Semi-transparent higher spread rateUpdated: July 2026
300 ÷ 175 = 1.7 gal per coat × 2 coats = 3.4 gal → 4 gallons. Clean and brighten before stain.
New wood accepts less on first coat — 400 ÷ 275 = 1.5 gal. Second coat 6–12 months later uses less product.
Add vertical and stair surface to deck footprint. Spindles consume extra stain — brush application uses more than pad on decking.
Calculate deck stain or sealer gallons for horizontal decking, rails, and steps. Enter deck area, board condition (new vs weathered), and product coverage to get gallons for one or two maintenance coats.