Calculate exactly how much paint you need for one or more rooms, based on wall (and optional ceiling) dimensions, with deductions for doors and windows.
Room
Length (ft)
Width (ft)
Height (ft)
Doors
Windows
Ceiling?
Enter coverage according to your paint/product.
How to Use the Paint Quantity Calculator
Add each room with its length, width, and height, plus its door and window count. Tick "Ceiling?" to include the ceiling area for that room.
Set the door/window area used for deductions, your paint coverage rate, and the number of coats.
Click "Calculate" to see the paintable area and required paint for each room and in total.
Frequently Asked Questions
Wall Area = 2 × (Length + Width) × Height — the perimeter of the room multiplied by wall height. Door and window areas are then subtracted to get the paintable area.
Coverage varies with paint type, the surface being painted, application method, number of coats, and manufacturer — there's no single fixed number. Check your paint tin's label for its stated coverage and enter that value here.
Yes, it's completely free and requires no sign-up.