Paint Calculator
Calculate how much paint you need for a room, including doors, windows, coats, and an optional ceiling — in liters, gallons, or cans.
How to measure a room for paint
Measure the length and width of the room, and the height of the walls. This calculator uses those to work out the total wall area, then subtracts a standard allowance for each door and window you enter.
Two coats is standard for most walls. Check your paint tin for its coverage rate — it varies by brand, finish, and surface texture — and adjust the coverage field to match.
Frequently asked questions
How much paint do I need for a room?
Multiply the wall perimeter by the wall height to get wall area, subtract standard door and window areas, then divide by your paint's coverage rate and multiply by the number of coats. This calculator does that for you.
How many coats of paint do I need?
Two coats is standard for most walls, especially over a different existing color. One coat may be enough for a fresh coat of the same color; three coats for very light colors over dark ones.
What paint coverage rate should I use?
Most interior paints cover roughly 10 m² per liter (about 350 sq ft per gallon), but check the label on your specific paint — coverage varies by brand, finish, and surface texture.
Should I paint the ceiling too?
Toggle "Include ceiling" to add the ceiling area to your total. Ceilings are often painted with a flatter finish than walls, so you may want a separate calculation if you're buying different paint for each.
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