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Paint Calculator (Square Feet)
Calculate how much paint you need for a room. Enter dimensions, number of doors and windows, and coats. Shows litres and gallons. Free, no signup.
Paint Calculator (Square Feet)
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About Paint Calculator (Square Feet)
When you already know the area in square feet, entering it directly is quicker than typing every wall. This page starts in US units and known area mode: put in the square feet, set the coverage from your paint can, usually 350 to 400 square feet per gallon, choose the coats, and read off the gallons. The arithmetic is simply area divided by coverage, multiplied by coats. At 350 square feet per gallon, 400 square feet over two coats needs about 2.3 gallons, which in practice means two gallons and a quart, or three gallons if you want paint left for touch-ups. To get the wall area of a room yourself, add the length and width, double it and multiply by the ceiling height, then take off about 20 square feet for each door and 15 for each window. A 12 by 14 foot room with 8 foot ceilings has 416 square feet of wall, or around 380 after one door and one window. This mode also suits awkward spaces like stairwells, open plans and gable ends that do not fit a rectangle. For metric areas see Paint Calculator m2, and for how far a can goes see How Much Does a Gallon of Paint Cover? (Sq Ft per Coat).
How to use Paint Calculator (Square Feet)
Enter room length, width, and wall height in metres or feet
Set the number of doors and windows to subtract their area
Choose number of coats and see litres and gallons needed
Frequently Asked Questions
How many gallons of paint per square foot?
At 350 square feet per gallon, one square foot needs about 0.003 gallons per coat. Put differently, every 350 square feet of wall needs one gallon for each coat.
How much paint for 1,000 square feet?
About 2.9 gallons for one coat and 5.7 gallons for two, at 350 square feet per gallon. At 400 square feet per gallon it drops to 2.5 and 5 gallons.
How do I find the square footage of my walls?
Add the room length and width, double it and multiply by the ceiling height. Subtract about 20 square feet per door and 15 per window. For a 12 by 14 room with 8 foot ceilings that gives about 380 square feet.
Should I round up the gallons?
Yes. Paint is sold in quarts, gallons and 5 gallon buckets, so round up to the next size you can buy, and keep a little extra for touch-ups. Buying it all at once also keeps the colour batch consistent.
Do I count the ceiling in square feet?
Only if you are painting it, and it is better calculated separately because ceilings usually use a different flat white paint. A ceiling is simply length times width.