Paint quantity calculator
How many paint tins for your room? Enter the dimensions, deduct doors and windows, pick your coverage and number of coats: the tool computes the real surface, volume in liters and the exact number of tins to buy.
Room dimensions
Openings to deduct
Standard includedEnter the number of doors (1.6 m²/u), windows (1.2 m²/u) and bay windows (4 m²/u). That area will be subtracted from the total.
Paint specs
Often indicated on the tin (e.g. 10 to 12).
Your result
Enter the dimensions to calculate.
Good to know :
This answer helps you understand a topic or make an estimate, but it is not a substitute for professional advice. For any important decision regarding your health, finances, rights, safety or administrative procedures, please consult an official source or a qualified specialist.
Go deeper
The right number of tins, first time
Buying too much paint is wasted money. Buying too little means a trip back to the shop at the worst time. This calculator gives a reliable estimate based on the 3 parameters that really matter: surface to paint, paint coverage and number of coats.
The formula
Number of tins = ceil( Volume ÷ Tin size )
Total surface is auto-computed: (Length + Width) × 2 × Height for walls, plus ceiling surface if ticked. We then subtract openings: 1.6 m² per door, 1.2 m² per window, 4 m² per bay window.
Coverage
Check the tin: most matte paints announce 10 to 12 m²/L. Satin or velvet: 8 to 10. On raw surface, divide by two.
Coats
2 coats is standard on a light-painted wall. Count 3 coats to cover a dark color or paint raw plasterboard.
Safety margin
Number of tins is always rounded up. You'll naturally have a bit of reserve for touch-ups.
Pro tips
- Primer is mandatory on new plaster, plasterboard or when changing from a dark color — it doesn't replace a topcoat but cuts consumption.
- Buy one large tin rather than two small ones: per liter, it's almost always cheaper.
- Same shade, same batch if possible: different batch numbers can drift slightly.
- Keep 0.5 L aside for post-move touch-ups: nail hole, chipped door corner, furniture mark.
FAQ
Which coverage should I enter for my paint?
Check the tin label: most matte acrylic paints announce 10 to 12 m²/L. For a satin or velvet finish, expect 8 to 10 m²/L. On a very porous surface (raw plasterboard, new plaster without primer), halve this coverage.
How many coats should I plan?
On a wall already painted in a similar tone, 2 coats is enough. To cover a dark color with a light one (or vice versa), plan 3 coats or first apply a dedicated primer.
Why deduct doors and windows?
Because you don't paint them! The tool subtracts 1.6 m² per door, 1.2 m² per window and 4 m² per bay window — reliable averages for typical homes.
Should I buy one large tin or several small ones?
A large tin is almost always cheaper per liter. It also avoids shade differences between tins. For a simple patch or a small room though, a 0.5 L or 2.5 L tin is plenty.
Is my data stored?
No. The calculation runs live in your browser, no data is sent to a server. You can close the tab without worry.
