Paint calculator
Measure the room, put the numbers in, and this works out the wall area, the litres, the tins to buy and a rough cost. It's the same arithmetic we do before we quote — useful if you're painting it yourself, or just want to know what's involved.
Your room
Measure the room in metres. If you don't know the ceiling height, 2.4m is a good default for a modern house.
Fill in the room and press Work it out — the numbers appear here.
How it works
Nothing hidden — this is exactly what the calculator does.
Perimeter (length + width, doubled) multiplied by ceiling height. Then we take off roughly 1.7m² for each door and 1.5m² for each window, because you don't paint the glass.
If you're painting the ceiling, the floor area goes on top of that.
Most emulsion covers about 12m² per litre per coat. So wall area divided by 12, multiplied by the number of coats.
Trim and skirting use a different product — we allow about 0.15 litres per door and 0.1 per window for the frames, plus a small allowance for skirting.
Paint comes in 1L, 2.5L and 5L tins. The calculator works out the cheapest sensible combination, so you're not buying five small tins when one big one would do.
It always rounds up — running out mid-wall is worse than having a bit left over for touch-ups.
How thirsty your walls are. Fresh plaster, bare timber and a big colour change all drink more paint than the average. Add 10–15% if any of those apply.
It also doesn't cover prep, filling, sanding or labour — that's what the quote is for.
Rather not do it yourself?
Send us the room sizes and we'll come back with a fixed price that covers the prep, the paint and the labour — and you don't have to own a single roller.