🎨 Room Paint Calculator

How many tins of paint do you actually need? Don't buy too much.

What this tool helps with

Litres of paint required

What you can enter

  • Total length of all walls (m): 14
  • Wall height (m): 2.4
  • Number of doors/windows: 2
  • Number of coats: 2

Why this page is useful

How many tins of paint do you actually need? Don't buy too much. This page loads fast, gives a direct answer, and then expands with useful context instead of burying the result under filler.

How the Room Paint Calculator works

The room paint calculator takes Total length of all walls (m), Wall height (m), Number of doors/windows and Number of coats and returns Litres of paint required. The calculation runs entirely in your browser — nothing is sent to a server, no sign-up, no tracking beyond standard analytics, and no waiting for results.

Under the hood the tool uses the same transparent formula people would apply by hand, just faster and without the arithmetic mistakes. If you want to sanity-check the output, the "Frequently Asked Questions" section below walks through the reasoning and edge cases.

When this is worth using

Most people land on a home & diy tools page like this when they want a quick, honest answer without a sales pitch. Typical moments include planning ahead, settling a debate, double-checking an assumption, or figuring out whether a rough idea actually holds up once you put numbers on it.

If you're going to repeat this calculation with different values, bookmark the page — it's designed to load instantly and give a clean result every time.

Getting a more accurate result

  • Use realistic inputs. Round numbers are fine for a first pass, but your actual figures will give a meaningfully better answer.
  • Try a few variants. Adjust one value at a time to see which inputs move the result the most — that's usually where it's worth focusing your attention in real life.
  • Cross-check with the related tools below. They cover adjacent questions and will flag anything that looks off.

Frequently Asked Questions

A standard 2.5L tin of emulsion covers about 30-35 square metres (one coat).
It's always wise to have a little left over for touch-ups later, but this calculator gives you the strict mathematical requirement.