Paint calculator — litres and gallons needed
Room dimensions, doors, windows, coats: get the amount of paint to plan for — and quote the job right.
In feet — 375 sq ft per gallon
North American standard, per coat.
In meters — 10 m² per litre
Metric standard (Europe), per coat.
Basis: 375 sq ft per gallon per coat (North America) · 10 m² per litre per coat (metric) · deductions: 20 sq ft (1.9 m²)/door, 15 sq ft (1.4 m²)/window. Plan ~10% extra for porous surfaces or covering dark colours.
Frequently asked questions
How many square feet does a gallon of paint cover?
About 350 to 400 sq ft per coat (we use 375 sq ft), depending on surface porosity and paint type. On new drywall or when covering a dark colour, plan for the low end.
How do I calculate the paintable area of a room?
Room perimeter × wall height, minus openings (about 20 sq ft per door and 15 sq ft per window). Add the ceiling (length × width) if you are painting it.
From quantity to quote
Paint quantity is only the start — you still need prep, repairs, labour and taxes. Our quoting app for painters shows how to build a painting quote that gets signed — and bookyoo generates it in 2 minutes, taxes included. Free 7-day trial.
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