Paint Calculator
How many gallons do you need? Find out in 10 seconds.
Pro Tips
How to Calculate Paint Like a Pro
The standard formula: measure the perimeter of the room (2 × length + 2 × width), multiply by ceiling height to get total wall area, subtract windows (15 sq ft each standard) and doors (21 sq ft each standard), then divide by 350 (coverage per gallon on smooth walls). Multiply by number of coats. Round up to the nearest gallon because you cannot buy partial gallons at most stores — and leftover paint is useful for future touch-ups anyway.
Where this formula fails: textured walls (stucco, knockdown, orange peel) absorb more paint and reduce coverage to 250-300 sq ft per gallon. Unpainted drywall absorbs heavily on the first coat — use a primer coat first, which costs half as much as finish paint and creates a uniform base that the finish coat covers evenly. Painting dark colors over light requires 2-3 coats; light over dark requires a tinted primer plus 2 coats of finish.
What Paint Costs in 2026
Budget paint (Behr Flat, Glidden): $25-35 per gallon. Mid-range (Benjamin Moore Regal, Sherwin-Williams SuperPaint): $50-70 per gallon. Premium (Benjamin Moore Aura, Sherwin-Williams Emerald): $70-90 per gallon. The price difference is not just marketing — premium paints have higher pigment concentration (better coverage in fewer coats), better adhesion, and superior washability. A $35 paint that requires 3 coats costs more in material and dramatically more in labor time than a $70 paint that covers in 2.
Should I paint the ceiling?
If the ceiling is stained, yellowed, or a different color than you want, yes. Ceiling paint is formulated to be thicker (less dripping) and is typically flat white. One gallon covers the ceiling of a 12×14 room. Always paint the ceiling first, then the walls — drips on unpainted walls do not matter.
How much does it cost to hire a painter?
Professional painters charge $2-6 per square foot of wall area, or $200-800 per room depending on size, complexity, and location. A typical bedroom costs $300-500 for two coats including material. DIY saves 60-70% but takes a full weekend per room for a beginner.