Handitab

Paint Calculator

Calculate how much paint you need from the wall area, the area of doors and windows, the number of coats, and the paint coverage.

About Paint Calculator

The amount of paint for a job depends on the surface to cover and how far the paint spreads. This calculator uses liters = (wall area − doors and windows area) × number of coats ÷ coverage, where coverage is the m² one liter covers in one coat, as stated on the can. The result is also given in US gallons (1 gallon = 3.785 liters) and as whole 5 liter and 1 gallon cans, rounded up.

How to use Paint Calculator

  1. Fill in "Wall area", "Doors and windows area", "Number of coats" and "Coverage".
  2. The result appears below and updates as you type.
  3. Copy the result with the copy button, or download it as a file where that is offered.

Questions about Paint Calculator

What coverage figure should I use?

Use the spreading rate printed on the can. Interior wall paint commonly covers 8 to 12 m² per liter per coat. New plaster, rough surfaces, and strong colour changes absorb more, so lower the figure for those.

How do I work out the wall area of a room?

Add the lengths of all walls to get the perimeter and multiply by the ceiling height. A room 4 m by 3 m with a 2.5 m ceiling has 14 m × 2.5 m = 35 m² of wall.

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