Paint calculator
Enter the room or the wall area, the coats and the coverage on the can. You get the gallons, and the mix of 5-gallon buckets, gallons and quarts to buy.
Inputs
Result
How it is worked out
A 12 by 10 ft room with 8 ft ceilings has 352 sq ft of wall. Less a door and two windows, 302 sq ft. Two coats at 350 sq ft a gallon is 1.73 gallons: buy two gallons, or a gallon and three quarts.
Coverage
The coverage printed on the can assumes a smooth, primed surface. Rough or porous surfaces drink paint: new drywall, bare wood, stucco and brick can need half as much again. Deep colours over light ones, or light over dark, often need a third coat or a tinted primer. When in doubt, use the low end of the range on the can.
Two gallons of the same colour can differ slightly. Mix them together in a bucket before you start, called boxing, so the walls match.
Questions
How many gallons of paint do I need for a room?
For a typical 12 x 10 ft bedroom with 8 ft ceilings, about 1.7 gallons for two coats on the walls. Buy two gallons; add another for the ceiling.
How much does a gallon of paint cover?
Most labels say 350 to 400 sq ft per gallon for one coat on a smooth, primed surface. Rough or unprimed surfaces get much less.
How many coats of paint do I need?
Two for most walls. One can be enough when repainting the same colour; a big colour change or bare drywall may need primer and two coats.
How much paint for a 1,500 sq ft house?
It depends on the wall area, not the floor area. Interior walls are often three to four times the floor area, so roughly 4,500 to 6,000 sq ft for two coats, or 13 to 17 gallons, plus ceilings.
Is a gallon enough for two coats?
A gallon covers 350 to 400 sq ft once, so two coats on up to about 175 to 200 sq ft of wall, an average bathroom.
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