Paint Calculator
Get the exact paint quantity for any room.
Enter your room's length, width, and wall height, plus how many coats you plan to apply. The calculator works out the wall area, the liters of paint you need, and the gallons for US shoppers. The default coverage of 10 m² per liter suits most interior paints.
How it's calculated
Wall area = 2 × (length + width) × height, then liters = wall area × coats ÷ coverage per liter. Gallons are liters ÷ 3.78541.
Frequently asked questions
How do I measure wall area for painting?
Multiply your room's length by its width to get the floor area, then multiply by the ceiling height and by 4 walls — or simply measure each wall. A 5 m × 4 m room with 2.7 m ceilings has about 48.6 m² of wall.
How much area does one liter of paint cover?
Most interior latex paints cover 8–12 m² per liter per coat. The default of 10 is a safe middle value — premium paints cover more, cheap or dark-color paints less.
Do I really need two coats?
Two coats is the standard for even color and durability. One coat may do for a refresh in the same color, but color changes and bare surfaces need two.