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.
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.
