Paint Calculator

Paint Calculator helps you work out, in seconds, how much paint a room or a whole project really needs — so you stop guessing at the store and stop running out halfway up the wall. It works completely offline and nothing you enter ever leaves your phone.

HOW IT WORKS
The calculator uses the standard painter's method:

1. It finds the wall area. For a box-shaped room that is the perimeter times the height: 2 × (length + width) × height. You can also type a wall area directly if you already have it.

2. It subtracts the doors and windows you won't paint.

3. It multiplies the paintable area by the number of coats, then divides by the coverage of one can — about 350 ft² per gallon for typical interior latex, and fully editable for your paint.

4. Because paint is sold by the whole can, it rounds the exact figure up and tells you how many gallons to buy.

WHAT YOU CAN DO
• Enter a room by length, width and height, or type the wall area straight in
• Subtract door and window area so you only buy what you need
• Choose the number of coats and set your paint's real coverage
• Read the gallons to buy as one big number, with the exact gallons, wall area, paintable area and total area beside it
• Add several rooms on the Rooms tab and get one combined amount for the whole job
• Switch between imperial (ft, ft²/gallon) and metric (m, m²/litre)
• Learn the formula, coverage tips and when to add a primer coat in a plain-language guide

BUILT FOR CLARITY
A clean, friendly design puts the number you came for first. Light and dark themes, a tiny download, no clutter and no account required.

A PLANNING ESTIMATE
Real coverage depends on your paint, the surface texture, the colour and how you apply it — rough or porous walls drink more paint, and deep colours can need an extra coat. Treat the result as a planning guide, check the coverage printed on your paint, and always buy a little extra for touch-ups. This app is for general information only and is not affiliated with any paint manufacturer.

PRIVACY
The app collects no personal data and works fully offline. Ads are served by Google AdMob, which may use an advertising identifier as described in Google's policies.

Download Paint Calculator and buy the right amount of paint the first time.