PaintCalc: Wall Paint

PaintCalc works out how much paint your walls take. Enter the total length of the walls and their height, subtract the doors and windows, set how many coats you are putting on, and it returns the gallons of paint, the net wall area and what it costs at your price per gallon.

WHAT YOU CAN DO
- Enter the total length of the walls you are painting and the wall height, in feet.
- Subtract doors and windows by count. Each door counts as 3 by 7 feet and each window as 4 by 4 feet.
- Set the number of coats.
- Change the coverage figure if your tin says something other than the 375 square feet per gallon the app starts with.
- Add primer with one toggle, costed as a single coat over the same net area.
- Enter your price per gallon and see the cost of the job.
- Watch the gallons, the net square feet and the cost update as you type.

HOW TO MEASURE
Measure each wall you are painting and add the lengths together. A ten by twelve room has 44 feet of wall around it. Enter that total with the wall height, then the number of doors and windows.

A WORKED EXAMPLE
40 feet of wall at 8 feet high is 320 square feet. Take away one door and three windows, 69 square feet, and 251 square feet are left to paint. Two coats at 375 square feet per gallon comes to 1.4 gallons once rounded up.

WHY THE OPENINGS MATTER
A ten by twelve room with a standard door and two windows loses roughly 50 square feet of wall. Over two coats at 375 square feet per gallon that is about a quarter of a gallon, bought and never opened. On a whole house it stops being small.

HOW IT ROUNDS
Gallons are rounded up to the next tenth, because you cannot buy a fraction of a tin and you should not be a cup short on the last wall. The area and the cost are given to two decimals.

WHO IT IS FOR
Anyone painting a room this weekend, and anyone quoting the job on Monday.

PRIVACY
No accounts, no analytics, no network requests. What you type stays on the device.