Paint & Finishes
Paint & Finishes Calculators
Free paint calculators for any room, exterior, or repaint job. Get gallons for walls, ceiling, primer, and trim — with door and window subtraction built in.
3 calculators · 5 reference pages
All Paint & Finishes calculators
Paint Calculator
Use this paint calculator to size up an interior repaint, exterior siding job, or accent wall.
Open calculatorRoom Paint Calculator
Plan an interior repaint by the room.
Open calculatorExterior Paint Calculator
Plan an exterior repaint by figuring the gallons of paint and primer for your siding.
Open calculator
Reference
Quick answers for paint & finishes
Quick answer
How Much Paint Do I Need?
Most rooms need 2 to 3 gallons of paint for two coats. A standard bedroom needs 2 gallons; a large living room with cathedral ceilings can need 4–5.
Quick answer
How Many Square Feet Does a Gallon of Paint Cover?
A US gallon of paint covers about 350 square feet in one coat on smooth, primed drywall. Textured or porous surfaces drop coverage to 250–300 ft².
Quick answer
How Much Does a Gallon of Paint Cost?
A gallon of interior paint costs $30 to $60 in 2026. Premium and exterior paints reach $60–$100 per gallon. Five-gallon buckets typically save 15%.
Quick answer
How Many Square Feet Does a Gallon of Paint Cover?
One gallon of interior latex paint covers about 350 square feet per coat — roughly the wall area of a small bedroom.
Quick answer
How Much Does 1 Gallon of Paint Cover?
One gallon of interior latex paint covers about 350 square feet per coat — enough for a small bedroom (12×12) with one coat on the walls.
FAQ
Frequently asked
A gallon of interior paint covers about 350 ft² per coat on smooth drywall, 250 ft² on textured surfaces. Most jobs need two coats — buy by the 5-gallon bucket for the best per-gallon price.
Spot-prime patched drywall and stained spots. Full primer is only needed when going from a much darker color to a lighter one or when painting bare wood/metal.