Calculator Uni

Paint Calculator

Work out how many gallons of paint a room needs.

Room details
ft
ft
ft

Paint needed

2.5 gal

rounded up to half-gallons

Wall area

356 sq ft

Coverage assumed

350 sq ft/gal

Quarts equivalent

9

The coverage math

Wall area is the perimeter times height, minus about 20 sq ft per door or window. A gallon covers roughly 350 sq ft on smooth, primed walls — textured or porous surfaces drink 25% more, and deep color changes usually demand two coats regardless of the label's promises.

Buy a little smart

Round up to the next half-gallon and keep the surplus for touch-ups — matching a custom tint two years later is chancy. One gallon of ceiling paint handles a typical 12×14 room; trim usually needs just a quart.

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