Paint Calculator: How Many Liters Do I Need?
Work out how many liters of paint and primer a room needs from its size, number of doors and windows and coats, plus which can sizes to buy.
How is it calculated?
Wall area = 2 × (width + length) × height. About 1.9 m² is subtracted for each door and 1.5 m² for each window; if you choose, the ceiling area (width × length) is added. The total is multiplied by the number of coats and divided by the paint's coverage (m² per liter).
Coverage
Interior paints usually cover 8–12 m² per liter per coat; the exact figure is printed on the can. Rough, absorbent or never-painted surfaces need more paint.
Can sizes
The result suggests a mix of 2.5 L, 7.5 L and 15 L cans that leaves as little over as possible. Keeping a little extra for touch-ups is a good idea.
Frequently asked questions
Do I need primer?
Primer is recommended on new plaster, filled or stained walls, and when going from a dark color to a light one. It helps paint stick and can reduce the number of coats.
How many coats should I apply?
Two coats are usually enough. Going from dark to light, or using paint with low hiding power, may need a third.
Other tools
Get quotes for painter
For an exact price, post your request and let verified pros in your area send quotes.