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How much paint do I need?
Work out litres and tins from your room size, coats and coverage.
Your room
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Your product12 m²/L · 5 L tins (best fit) · 2 coatsChange
Using 5 L tins — the fewest tins, in the smallest size that covers it.
2 × 5 L tins
- Wall area
- 32.1 m²
- × 2 coats ÷ 12 m² per litre
- 5.3 L
- ÷ 5 L tins
- 2 tins
about 4.7 L spare
How we work it out
- We work out the paintable area of your walls, floor or ceiling, taking off standard doors and windows automatically.
- That area is multiplied by your number of coats, then divided by the tin's coverage rate to give litres.
- Litres are rounded up to whole tins - you can't buy part of a tin, so we always round in your favour to avoid a second trip.
- Coverage rates vary a lot by paint type and wall texture, so use the figure on your chosen tin's label if you have it rather than the default.
Frequently asked questions
How much paint do I need for a 3x4m room?
For a typical 2.4 m ceiling with one door and one window, that's roughly 25 m² of wall. At two coats and 12 m² coverage per litre, that's about 4.2 litres - so two 2.5 L tins. Enter your own numbers above for an exact figure.
How many coats of paint do I actually need?
Two coats is standard for a fresh, even finish, especially over a different colour. One coat can work for a like-for-like refresh; three is sometimes needed for strong colour changes like dark-to-light.
What's a typical coverage rate for emulsion?
Most UK emulsions cover around 12 m² per litre on a smooth, previously painted wall. Textured or very absorbent surfaces (new plaster, woodchip) can drop that to 8-10 m² per litre - check your tin's datasheet.
Should I round up or down when buying paint?
Always round up to the next whole tin. Running out mid-wall means a delay waiting for more, and matching a batch exactly later isn't guaranteed - a bit of spare paint is also handy for touch-ups.
Want to see this in your actual room? Try it with DreamDIY