Free Tool
Free paint calculator
Enter the room size, doors, windows, and coats and get the gallons to buy. Coverage and standard opening sizes are built in, so you order right the first time. Free, no signup.
Private by design — everything you type stays in your browser. Nothing is uploaded, stored, or seen by us.
Buy the right amount of paint
Running out mid-wall means a second trip and a visible lap mark where the paint dried. Buying way over means cans stacking up in the garage. This gets you close.
The calculator figures your wall area, subtracts the doors and windows, and multiplies by your coats. It uses 375 square feet per gallon, which is a safe middle for most wall paint. Flat paints stretch further, deep colors and rough walls less.
Two coats is standard over a similar color. Plan on three over a big color change or bare drywall. The tool rounds up to whole gallons so you have a little extra for touch-ups down the road.
Questions
How much does a gallon of paint cover?
About 350 to 400 square feet in one coat. The calculator uses 375 as a safe default. Adjust it for the specific product if you know its coverage.
How many coats should I plan for?
Two over a similar color. Three over a big color change, a stain, or bare drywall that has not been primed.
Is this really free?
Yes. No email, no signup, and nothing you type leaves your browser.
Turn the takeoff into a priced estimate
Werx takes your quantities and builds a branded estimate and proposal in one step, then tracks the real cost as you paint. 14-day free trial, no credit card.
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Disclaimer: These free tools and templates are provided for general information and estimating purposes only. All results — including quantities, material and cost estimates, load, sizing, and span figures, scores, and any guidance or warnings — are rough approximations that may not fit your specific project, site conditions, local building codes, or current prices. They are not engineering, architectural, structural, legal, financial, or other professional advice, and are not a substitute for a licensed engineer, architect, contractor, or other qualified professional. Always confirm quantities, sizing, and structural, electrical, mechanical, and code requirements with a licensed professional and your local authority having jurisdiction before purchasing materials or performing any work. Werx makes no warranty as to accuracy and accepts no liability for any decision made using these tools. Use at your own risk. See our Terms of Service.