Paint Calculator

How much will you actually need?

Measure what you’re painting, tell us how many coats, and we’ll estimate the litres. It’s a guide based on the manufacturers’ published coverage, and it’s worth reading what it can’t account for before you buy.

The surface

Width (m)

Height (m)

One surface at a time. For four walls, add their widths together and use the ceiling height. For a ceiling, use its own two measurements.

The paint

Coats

Brand

Coverage figures are each manufacturer’s own, for their standard interior emulsion on a smooth, prepared, previously-painted surface. Other finishes, and bare plaster, differ, sometimes a lot.

An estimate, not a quote

This calculator does straightforward arithmetic on the numbers you type in and the coverage the manufacturer publishes for their standard interior emulsion. It has never seen your walls, so please treat the answer as a sensible starting point rather than a promise.

Things that will change what you actually need, none of which the calculator can know:

Bare or newly skimmed plaster drinks paint, and wants a thinned mist coat first, so expect to use noticeably more.
Textured, papered or previously glossed surfaces take more than a smooth wall.
A strong colour over a much lighter one (or the other way round) often needs a third coat.
Different finishes cover differently. The figure used here is for emulsion; primers, undercoats, eggshell, gloss, limewash, floor and exterior paints all differ.
Sloping ceilings, alcoves, panelling and deep reveals add area a width × height sum misses.
Tin sizes are not the same across a range. Emulsion comes in 1, 2.5 and 5 litres plus sample pots. 750ml is an eggshell and woodwork size, and is not available in emulsion in any of the brands we stock.

We include a 10% margin, which covers most of the ordinary surprises but not all of them.

These figures are an estimate and nothing more. We can’t accept responsibility for paint or paper ordered on the strength of them alone, or for what it costs to put right. If the job matters, and it usually does, bring your measurements in to 41 Bridge Street, Godalming. Checking it over with you takes two minutes and costs nothing.