Enter your floor’s dimensions, number of coats, and the coverage listed on your product to find out how many gallons of epoxy you need to buy. Works for garage floors, basements, and workshops — 100%-solids, water-based, and resin systems alike.
How to use this calculator
- Enter the floor’s length and width in feet.
- Set the number of coats (2 is typical) and the coverage per gallon from your product label.
- Adjust the waste factor and optionally add the price per gallon for a cost estimate.
The math behind it
Gallons = area (sq ft) × coats ÷ coverage (sq ft per gallon per coat), plus the waste factor, rounded up to whole gallons. Coverage varies enormously by product — around 50 sq ft/gal for thick 100%-solids epoxy, 150+ for thin water-based formulas.
FAQs
How much epoxy for a 2-car garage?
A 20×20 ft (400 sq ft) garage at 2 coats and 100 sq ft/gal coverage needs about 9 gallons including waste — run your numbers above.
Why do coverage numbers vary so much?
Thickness. A gallon spread at 32 mils covers ~50 sq ft; the same gallon at 10 mils covers ~160 sq ft. Always use the figure on your product’s label.
What mix ratio do I need?
Most systems are 2:1 or 4:1 resin to hardener. Buy enough of both parts, and only mix what you can apply within the pot life.