Is this paint calculator free?

Yes, completely free with no signup required.

Does my data leave my device?

No. All calculations happen in your browser — nothing is sent to a server.

Does it work on mobile?

Yes. The tool is mobile-first and works on any modern browser.

How much paint does a gallon cover?

Standard interior paint covers roughly 350 sqft per gallon per coat. High-build primers may cover less. Always buy 10% extra for touch-ups and texture variation.

Should I use 1 or 2 coats?

Two coats give the best color coverage and durability. One coat may suffice when painting a similar color on top of a well-primed, smooth surface.

Paint Calculator

Calculate how many gallons of paint you need for walls and ceilings by room dimensions.

100% client-side · no upload

Room length (ft) Room width (ft) Ceiling height (ft) Number of doors Number of windows Number of coats

How to use

Enter your room length, width, and ceiling height in feet.
Add the number of standard doors (20 sqft each) and windows (15 sqft each) to subtract from the painted area.
Set the number of coats — results update instantly showing gallons needed.

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Frequently Asked Questions

Is this paint calculator free?: Yes, completely free with no signup required.
Does my data leave my device?: No. All calculations happen in your browser — nothing is sent to a server.
Does it work on mobile?: Yes. The tool is mobile-first and works on any modern browser.
How much paint does a gallon cover?: Standard interior paint covers roughly 350 sqft per gallon per coat. High-build primers may cover less. Always buy 10% extra for touch-ups and texture variation.
Should I use 1 or 2 coats?: Two coats give the best color coverage and durability. One coat may suffice when painting a similar color on top of a well-primed, smooth surface.

Last updated: 2026-05-20 By jarvisbox