Paint coverage calculator
Enter the room size and ceiling height, deduct doors and windows, choose coats and the paint's coverage, and get litres per surface and the tins to buy. Emulsion, trade matt or masonry — set the coverage and it does the rest.
Room dimensions
Paint type
Pricing the job? Open EstiMate free and these quantities go straight onto the materials list with your prices.
How it works out the quantities
- 1Wall area = perimeter × height minus openings; ceiling area = length × width.
- 2Litres = area × coats ÷ coverage per litre. Typical emulsion covers 12–14 m² per litre per coat; mist coats on fresh plaster less.
- 3Tin sizes (2.5 L, 5 L, 10 L) are recommended to minimise leftover while keeping one batch.
- 4Dark-to-light colour changes and bare plaster usually need an extra coat — add it in the coats field.
Site tips before you order
- Mist coat new plaster (watered-down emulsion) before two full coats; it's a separate line on the quote.
- Woodwork is priced by linear metre of skirting, architrave and per door leaf — not by wall area.
- Masonry paint covers far less (4–6 m²/L on rough render); change the coverage figure.
- Include filling, sanding and caulking as prep; that's where decorating quotes go wrong.
Common questions
How much paint for a 4 m × 3 m room with 2.4 m ceilings?
Walls about 33.6 m² minus openings (say 30 m²), two coats at 13 m²/L = about 4.6 L — a 5 L tin. Ceiling 12 m², two coats = about 1.9 L — a 2.5 L tin.
How many m² does a litre of emulsion cover?
Around 12–14 m² per coat on a smooth, previously painted wall; 8–10 m² on new plaster or textured surfaces.
How many coats do I need?
Two full coats over a similar colour; a mist coat plus two on bare plaster; three when going from dark to light.
Does the calculator deduct doors and windows?
Yes — enter the number of standard doors and windows or their areas and they come off the wall area.
Related calculators
Plastering calculator
Enter the wall and ceiling areas and choose the system — skim only, board and skim, or two-coat to masonry. Th…
Flooring calculator
Enter the room dimensions and the flooring type, and get the number of packs or square metres, the underlay, a…
Stud partition calculator
Enter the wall length and height and choose the stud centres. The calculator returns studs, noggins, plates, p…
Quantities are half the quote. EstiMate does the other half.
Drop the numbers into a priced, branded quote your client can accept online — free for your first three jobs a month.
Try EstiMate freeNo credit card · Free plan always available · Cancel anytime