Free Paint Calculator – Gallons, Liters & Cost
Free paint calculator to estimate gallons or liters needed for any room. Accounts for doors, windows, multiple coats, and coverage rate per gallon.
Paint Calculator Guide
The Paint Calculator determines how many gallons or liters of paint you need for a room. Enter the room width, length, and height, then specify the number of doors and windows to deduct. The calculator accounts for standard coverage per gallon and the number of coats.
Standard paint coverage is 350 sq ft per gallon for smooth walls. Textured walls, porous surfaces, or dark colors may require more paint. Two coats are recommended for most projects — the first coat provides base coverage and the second coat ensures full, even color.
Always buy slightly more paint than calculated and keep the leftover for touch-ups. Paint from different batches can have subtle color variations, so having extra from the same batch is valuable. Store leftover paint in a sealed container in a cool, dry place.