Paint Calculator
Calculate how many liters of paint you need for a room, accounting for doors and windows.
Estimating the right amount of paint prevents waste and ensures you do not run short mid-project, which can cause visible colour differences between batches.
This calculator computes the total wall area of a rectangular room (perimeter times height), subtracts the area of doors (approx. 1.89 m² each) and windows (approx. 1.39 m² each), multiplies by the number of coats, and divides by the coverage rate of 10 m² per liter — a standard rate for quality interior emulsion paint.
Textured or porous surfaces absorb more paint, so use 8 m² per liter for rough walls. Darker colours over light bases may need three coats. Always use a primer coat on new plaster or bare wood before applying your topcoat.