How much paint do I need for new plaster? A table by room size
A 3 × 4 m room (9.8 × 13.1 ft), 2.4 m high, with one door and one window, needs 10.154 L of wall paint and 3.96 L of ceiling paint for 2 coats and a mist coat at 10 m² per litre with 10% extra: 1 × 10 L tin + 1 × 2.5 L tin (12.5 L) for the walls and 1 × 5 L tin (5 L) for the ceiling. On walls painted before, the same room needs 6.77 L and 2.64 L: the mist coat is the difference. These are generic example figures, not a product’s: use the coats, coverage and tin sizes on your tin.
| Room | In feet | Wall paint needed | Wall paint to buy | Ceiling paint needed | Ceiling paint to buy | Your room |
|---|---|---|---|---|---|---|
| 2 × 2 m | 6.6 × 6.6 ft | 5.402 L | 1 × 5 L tin + 1 × 2.5 L tin (7.5 L) | 1.32 L | 1 × 2.5 L tin (2.5 L) | Open 2 × 2 m in the planner |
| 2.5 × 3 m | 8.2 × 9.8 ft | 7.778 L | 1 × 10 L tin (10 L) | 2.475 L | 1 × 2.5 L tin (2.5 L) | Open 2.5 × 3 m in the planner |
| 3 × 3 m | 9.8 × 9.8 ft | 8.57 L | 1 × 10 L tin (10 L) | 2.97 L | 1 × 5 L tin (5 L) | Open 3 × 3 m in the planner |
| 3 × 3.5 m | 9.8 × 11.5 ft | 9.362 L | 1 × 10 L tin (10 L) | 3.465 L | 1 × 5 L tin (5 L) | Open 3 × 3.5 m in the planner |
| 3 × 4 m | 9.8 × 13.1 ft | 10.154 L | 1 × 10 L tin + 1 × 2.5 L tin (12.5 L) | 3.96 L | 1 × 5 L tin (5 L) | Open 3 × 4 m in the planner |
| 3.5 × 4 m | 11.5 × 13.1 ft | 10.946 L | 1 × 10 L tin + 1 × 2.5 L tin (12.5 L) | 4.62 L | 1 × 5 L tin (5 L) | Open 3.5 × 4 m in the planner |
| 4 × 4 m | 13.1 × 13.1 ft | 11.738 L | 1 × 10 L tin + 1 × 2.5 L tin (12.5 L) | 5.28 L | 1 × 5 L tin + 1 × 2.5 L tin (7.5 L) | Open 4 × 4 m in the planner |
| 4 × 5 m | 13.1 × 16.4 ft | 13.322 L | 1 × 10 L tin + 1 × 5 L tin (15 L) | 6.6 L | 1 × 5 L tin + 1 × 2.5 L tin (7.5 L) | Open 4 × 5 m in the planner |
| 5 × 5 m | 16.4 × 16.4 ft | 14.906 L | 1 × 10 L tin + 1 × 5 L tin (15 L) | 8.25 L | 1 × 10 L tin (10 L) | Open 5 × 5 m in the planner |
| 5 × 6 m | 16.4 × 19.7 ft | 16.49 L | 1 × 10 L tin + 1 × 5 L tin + 1 × 2.5 L tin (17.5 L) | 9.9 L | 1 × 10 L tin (10 L) | Open 5 × 6 m in the planner |
Each row is the planner’s answer for that room, worked out when this page was built. The link at the end of a row opens the planner with that room filled in, to change the measurements and the product figures.
For every room, the planner warns: Older paint can contain lead and textured coatings applied before 2000 can contain asbestos: do not sand or scrape a coating you are not sure about; get advice first.
The mist coat is the first coat on bare plaster: the same emulsion, thinned with water as the tin says, counted here as one coat more of it. Mist coat ratio for new plaster has what each maker says about the water, and some paints use a primer-sealer instead.
New plaster must be dry before it is painted, and the plaster maker's instructions give the time. The coats, the coverage and the tin sizes are the planner's generic examples: the figures on your tin replace them.
What the table assumes
Each room is a rectangle 2.4 m high, with one door 0.762 m × 1.981 m and one window 1.2 m × 1.1 m.
- 1 door, 1 window taken off the wall area; nothing is taken off the ceiling or the floor.
- Wall paint and ceiling paint are separate products and are never added together.
- Every quantity is rounded once, at the end, up to whole packs. Working uses unrounded figures.
- Decorator's caulk, masking tape and dust sheets or protective sheeting: counted in the size each is typically sold in, from makers' own pages read on 6 October 2026. The label on what you buy says its real size.
- The figures for wall paint and ceiling paint are generic examples, not the figures of any product. Enter the figures from the tin or pack for a closer answer.
- 2 coats and a mist coat (generic example)
- 10 m² per litre (generic example)
- 10% allowance (generic example)
How this table was made
It was worked out when this page was built, by the same room planner and formulas as the editable list: each row is one room sent through the planner. The room sizes are round examples. Product coverage, pack and allowance figures are the planner’s labelled generic examples, not figures for a product.
AI tools drafted the page and automated tests compare every cell with the planner. It has not been checked by a tradesperson or anyone outside the build. No price is shown or used.
Before you use it
Measure your own room, its doors and its windows. Check the figures against the room, and follow each product's own instructions: they decide coverage, coats and preparation.
Built and checked with AI tools, not yet by a tradesperson or anyone outside the build. Estimates are arithmetic on your measurements and the figures shown with them: follow each product's own instructions.