Paint Calculator
Work out how many litres of paint and how many tins you need from your wall size, doors and windows, number of coats and the coverage on the tin.
- Free
- No sign-up to try
- Works as you type
Paint needed
Paint needed
7.2 L
Tins to buy
3
Area to paint
36.0 m²
- Area = total wall width × height − doors and windows.
- Paint = area × coats ÷ coverage per litre.
- Tins = paint ÷ tin size, rounded up.
Free, no sign-up to try. Save it as a live calculator you can share; an estimate from the numbers you enter, not financial advice. Check the result against your own records before you rely on it.
How it works
How the Paint Calculator works
- 1
Enter your numbers
Every result updates as you type, with the formula shown under it.
- 2
Check the method
See how each number is worked out and what it assumes.
- 3
Save it as a Room
Share a live calculator: others can change the numbers and see the result update.
Worked example
What it makes
Example inputs
- Total width of the walls
- 16 m
- Wall height
- 2.5 m
- Doors and windows to leave out
- 4 m²
- Coats
- 2
- Coverage per litre (on the tin)
- 10 m²/L
- Tin size
- 2.5 L
Results
- Paint needed
- 7.2 L
- Tins to buy
- 3
- Area to paint
- 36.0 m²
How it's calculated
- Area = total wall width × height − doors and windows.
- Paint = area × coats ÷ coverage per litre.
- Tins = paint ÷ tin size, rounded up.
- Assumes: Coverage is the figure on the tin; rough, porous or dark-to-light surfaces take more.
- Assumes: Ceilings and trim are not included: add them as extra wall width or work them out separately.
An estimate from the numbers you enter, not financial advice. Check the result against your own records before you rely on it.
Who it's for
Who uses it
Homeowners
Buy enough paint for a room in one trip.
Decorators
Include paint quantities in a quote.
Landlords
Budget paint for a refresh between tenants.
Good to know
What to consider
- Coverage on the tin is for smooth, primed walls: rough, porous or strongly coloured surfaces take more.
- Ceilings and trim are not included: add them as extra wall width or work them out separately.
Questions
About the Paint Calculator
How many coats do I need?
Two coats is the usual guide for an even finish. A big colour change, a dark colour or bare plaster may need a primer or a third coat.
Can I share the calculator with my team or a client?
Yes. The Room keeps the calculator live: anyone with the link can change the numbers and see the result update, with the method and assumptions on the same page.
Make your calculator now
Free, no sign-up to try. It becomes a Room you can edit, publish and share.
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