Paint Calculator
Estimate how much paint you need for a room's walls and ceiling — in liters or gallons — subtracting doors and windows, for one or two coats.
Your room
Paint needed
1 gallon covers ~350 sq ft; 1 liter covers ~8.6 sq m, per coat.
Frequently asked questions
How much area does a gallon of paint cover?
One gallon of latex paint typically covers about 350–400 square feet per coat. One liter covers roughly 10–12 square meters, which is what this calculator uses.
How do I calculate the paint needed for a room?
Add up the wall areas (perimeter × wall height), add the ceiling, subtract doors and windows, then divide by the paint coverage for the number of coats. The calculator does all of this.
Is one coat of paint enough?
Two coats are usually recommended for even, lasting coverage — especially over deep or contrasting colors. The calculator lets you toggle between one and two coats.
Should I subtract doors and windows?
Yes — subtract roughly 21 square feet per standard door and 15 square feet per standard window so you do not overbuy paint.
Why should I buy a little extra paint?
Touch-ups, trim, and waste mean you rarely use exactly the calculated amount. A few percent over or rounding up to the next can is the practical move.