TOOLS & CALCULATORS

Paint Calculator

Work out how much paint your walls need before choosing a tin. Add your measurements and use the coverage printed on your chosen paint.

Free to use. No account needed. Your measurements stay in this page.

Your room

Add each rectangular wall separately. For unusual shapes, split the surface into rectangles without counting any area twice.

Your paint

Two coats is an editable starting value, not a product recommendation. Check your paint’s coat requirements. Primer is not included.

Before you buy

Use the right coverage figure

Enter the product’s coverage for one coat. If its label gives a range, compare both ends to see how the estimate changes. In feet mode, the calculator uses US gallons, not UK imperial gallons.

Measure what you will paint

Subtract only doors and windows you are leaving unpainted. Add a door you plan to paint as a separate surface, using coverage suitable for its paint.

Keep primer separate

This result covers the finish paint you entered. A bare, repaired or previously painted surface may need a different preparation system. Check the chosen product before ordering.

A few useful answers

How does this calculator work?

It subtracts openings from each wall, adds the remaining areas, multiplies by the number of coats and divides by coverage per coat. Your optional percentage is added after that. Tin count is rounded up only after the allowance is included.

Does this work for a ceiling?

Yes. Add its length and width as another rectangular surface if you will use the same paint, coverage and number of coats. Run a separate calculation if those differ.

Can I use this for wallpaper?

No. Wallpaper needs a roll calculation that considers roll dimensions and pattern repeat. This page estimates paint only.