A 4 × 3 m bedroom
Walls 2.5 m high plus ceiling, one door and two windows: 42.2 m²; two coats at 10 m²/L with 10 % extra: 9.28 L, i.e. 4 cans of 2.5 L.
Paint calculator
Enter the size of the room, the doors and windows, the number of coats and the coverage printed on the can: PRAXAO calculates the area to paint, the litres needed with a small margin, and how many cans to buy.
Enter the dimensions to see the drawing.
Calculation results
Fill in the fields to see the result.
Preliminary estimate from the values entered: not a structural validation and not an execution plan. Check the local rules and the manufacturers’ data.
Your last inputs are kept in this browser.
Results are provided for information. Check tax rates and legal requirements that apply to you.
How to use it
- Enter the room length, width and wall height.
- Tick the ceiling if you paint it too.
- Enter the number and size of doors and windows.
- Set coats, coverage (from the can) and can size, then read litres and cans.
Examples
Frequently asked questions
How do I calculate the wall area of a room?
Perimeter × height: 2 × (length + width) × height, minus doors and windows.
Where do I find the coverage?
On the can, in m² per litre per coat. It depends on the product and on the surface: porous or rough walls absorb more.
How many coats do I need?
Usually two. Plan for a primer or a third coat on new plaster, dark colours or strong colour changes.
Guides to go further
BUILIVA
How much paint do you need for a room?
Wall area, openings, coats, coverage and waste: the method to buy the right number of cans, with an example.
BUILIVA
How many tiles do you need for a floor or a wall?
Area, tile and joint size, waste margin and boxes: the method to order enough tiles from the same batch, with an example.
Next step
- Turn this calculation into a quoteCarry the quantities into a priced quote, ready to send to your client.
- All tools in the “Painting” category
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Quote Generator
Prepare a clear quote or estimate for your client, with validity date, taxes and totals, ready as PDF.