How Much Paint Do I Need for a Room?
Short answer: a typical 4 m by 3.5 m double bedroom with 2.4 m walls needs about 5.5 litres of emulsion for two coats on the walls, or about 7.8 litres if you paint the ceiling too. Smaller bedrooms need around 3 to 4 litres. The tables below cover common UK rooms.
The paint formula
Work out the wall area, take off the doors and windows, then multiply by the number of coats and divide by the coverage printed on the tin.
Litres = area × coats ÷ coverage per litre
Our calculator counts a standard internal door as 1.6 m² and an average window as 1.5 m². It uses 12 m² per litre as the default coverage, which sits in the 10 to 13 m² range most emulsions print on the tin for smooth, sealed walls.
Paint for common UK rooms
All rooms below have 2.4 m walls, two coats and 12 m² per litre.
| Room | Size | Doors, windows | Wall area | Walls only | Walls and ceiling |
|---|---|---|---|---|---|
| Box room | 2.5 × 2.0 m | 1, 1 | 18.5 m² | 3.1 litres | 3.9 litres |
| Small bedroom | 3.0 × 2.5 m | 1, 1 | 23.3 m² | 3.9 litres | 5.1 litres |
| Kitchen | 4.0 × 3.0 m | 2, 1 | 28.9 m² | 4.8 litres | 6.8 litres |
| Double bedroom | 4.0 × 3.5 m | 1, 1 | 32.9 m² | 5.5 litres | 7.8 litres |
| Main bedroom | 4.5 × 4.0 m | 1, 2 | 36.2 m² | 6.0 litres | 9.0 litres |
| Living room | 5.0 × 4.0 m | 1, 2 | 38.6 m² | 6.4 litres | 9.8 litres |
| Large living room | 6.0 × 4.5 m | 2, 2 | 44.2 m² | 7.4 litres | 11.9 litres |
| Hallway | 4.0 × 1.2 m | 4, 0 | 18.6 m² | 3.1 litres | 3.9 litres |
Kitchens and bathrooms often have tiles or units covering part of the walls, so measure only the painted area for those rooms. Hallways with stairs have much taller walls; measure the full height on the stair side.
How many tins to buy (walls only)
| Room | Litres | 2.5 litre tins | 5 litre tins |
|---|---|---|---|
| Box room | 3.1 | 2 | 1 |
| Small bedroom | 3.9 | 2 | 1 |
| Kitchen | 4.8 | 2 | 1 |
| Double bedroom | 5.5 | 3 | 2 |
| Main bedroom | 6.0 | 3 | 2 |
| Living room | 6.4 | 3 | 2 |
| Large living room | 7.4 | 3 | 2 |
When the figure is just over a tin size, a 5 litre tin plus a 2.5 litre tin is usually the cheaper mix. A double bedroom at 5.5 litres fits that pattern.
What changes the amount
For the same 4 m by 3.5 m bedroom (two coats, one door, one window), the coverage and wall height make a real difference:
| Change | Paint needed |
|---|---|
| 10 m² per litre (thick or budget paint) | 6.6 litres |
| 11 m² per litre | 6.0 litres |
| 12 m² per litre (default) | 5.5 litres |
| 13 m² per litre | 5.1 litres |
| 2.3 m walls | 5.2 litres |
| 2.5 m walls | 5.7 litres |
| 2.7 m walls (many Victorian homes are taller still) | 6.2 litres |
| One coat only | 2.7 litres |
| Three coats (strong colour change) | 8.2 litres |
Worked example: a 5 m by 4 m living room
The walls are 2 × (5 + 4) × 2.4 = 43.2 m². Take off one door (1.6 m²) and two windows (3.0 m²): 38.6 m². Add the ceiling, 5 × 4 = 20 m², for a total of 58.6 m².
Two coats at 12 m² per litre: 58.6 × 2 ÷ 12 = 9.8 litres. Most people use a separate white ceiling paint, so split it: about 6.4 litres for the walls and 3.3 litres for the ceiling. For the walls buy one 5 litre tin and one 2.5 litre tin of colour (or three 2.5 litre tins). For the ceiling, two 2.5 litre tins or one 5 litre tin of white, which leaves some for touch ups.
Practical tips
- New plaster. Fresh plaster soaks up paint. It needs a thinned mist coat first, so add roughly one extra coat to your total.
- Dark to light. Covering a dark colour with a pale one often needs three coats, or a coat of primer first.
- Same batch. Buy all the tins for a room at once so the colour matches from wall to wall.
- Woodwork is separate. Skirting boards, doors and frames use gloss or satinwood, which is sold in smaller tins and is not included above.
- Floors next? Work out flooring with the square metre calculator, or tiles for a kitchen or bathroom with the tile calculator.
Try the paint calculator (litres)
Enter your own numbers below, or open the full paint calculator (litres) with the formula and more examples.
This guide is general information with example numbers, not financial, tax or building advice. Your costs and results will differ. Terms
Frequently asked questions
How much paint do I need for a 3 by 3 metre room?
With 2.4 m walls, one door and one window, the walls are 25.7 m², so two coats at 12 m² per litre need about 4.3 litres. Two 2.5 litre tins will do it.
How many litres of paint for a bedroom?
About 3.9 litres for a 3 m by 2.5 m small bedroom and about 5.5 litres for a 4 m by 3.5 m double bedroom, for two coats on the walls.
How much paint for a ceiling?
Ceiling area is length × width. A 4 m by 3.5 m ceiling is 14 m², so two coats at 12 m² per litre need about 2.3 litres.
Is one 5 litre tin enough for a room?
For a box room, small bedroom or most kitchens, yes. A double bedroom or living room usually needs 5.5 to 7.5 litres for two coats on the walls.