Free Online Tool

Paint Calculator — Estimate Paint Instantly

Calculate how much paint you need for walls, ceilings, and trim. Get accurate gallon estimates and material costs in seconds.

5
Paint Types
2
Systems
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Surfaces
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Enter your room dimensions and click Calculate to see paint estimates.

Frequently Asked Questions

Measure the length, width, and height of your room. Calculate the total wall area by adding the area of each wall, then subtract doors (21 sq ft each) and windows (15 sq ft each). Divide by the paint coverage rate of 350 sq ft per gallon, then multiply by the number of coats.
A standard gallon of paint covers approximately 350–400 square feet. For accuracy, this calculator uses 350 sq ft per gallon. Coverage can vary based on surface texture, color change, and application method.
Flat paint hides imperfections but is hard to clean. Eggshell has a slight sheen and is washable. Satin is durable for high-traffic areas. Semi-gloss is ideal for trim and kitchens. Gloss offers a shiny, durable finish for cabinets and doors.
Primer is recommended when painting over dark colors, bare drywall, wood, or metal surfaces. It improves adhesion, blocks stains, and ensures even coverage. This calculator estimates primer at one coat based on total wall area.
Trim paint is estimated based on the room's linear feet of baseboards and door/window casings. A standard room requires approximately 1 quart for trim. This calculator estimates trim paint assuming standard baseboard height and casing widths.
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