How much paint do I actually need?
A quick guide to coverage, coats and avoiding waste.
Buying paint twice is annoying; throwing half a bucket away is worse. Estimating properly takes five minutes and three numbers: wall area, coverage per litre, and number of coats.
The quick formula
Measure the perimeter of the room and multiply by wall height to get gross wall area. Subtract roughly 1.5 m² per door and 1 m² per window. Then: litres = (net area × coats) ÷ coverage. Most quality emulsions cover 10–12 m² per litre per coat on a sealed surface; fresh plaster and rough render drink considerably more, so budget 30–40% extra for a first coat on new walls.
Two coats is the honest default. Strong colour changes (light over dark, or vivid reds and yellows) may need a tinted undercoat or a third coat — cheaper than four coats of topcoat.
Skip the maths
Our paint calculator does all of this for you, per product, including coats and surface type — and a quote from our team locks in exactly what to buy. Measure once, paint once.
Ready to bring colour home?
Estimate your paint, explore shades, or talk to a colour consultant.