CalculatorAsphalt

Epoxy Calculator

Epoxy gallons and kits from floor area and target mil thickness.

Quick answer: One gallon covers 1,604 sq ft at 1 mil: coverage = 1,604 ÷ target mils. Garage coatings run 2 coats: ~10 mil primer-color plus topcoat. Concrete must be profiled and moisture-tested first.

How to use this calculator

  1. Enter Floor area in sq ft.
  2. Enter Thickness in mils — or tap a preset badge to auto-fill a typical value.
  3. Press Calculate. The highlighted row is your order quantity; the note beneath it translates the number into real-world terms.

Formula & constants

One gallon covers 1,604 sq ft at 1 mil: coverage = 1,604 ÷ target mils. Garage coatings run 2 coats: ~10 mil primer-color plus topcoat. Concrete must be profiled and moisture-tested first. Every default in the fields above is editable — when your supplier’s spec sheet lists a different density, coverage rate or price, enter that number instead. The waste and compaction allowances follow common trade practice; see our methodology page for the derivation of each formula and the standards it references.

Worked example. With floor area = 10 sq ft, thickness = 20 mils, the calculator returns:
Epoxy needed0.12 gallons
3-gal kits1 kits

Where this fits in the project

Coating and finish quantities are coverage-rate problems: true surface area divided by the product’s rated coverage, plus a waste allowance. Prep drives success — a coating over unprofiled or damp concrete fails regardless of quantity accuracy.

How this connects to your project

No quantity stands alone — each material in the chain depends on the ones around it. These are the planning steps that pair with the epoxy calculator:

Frequently asked questions

Why do epoxy floors peel?

Skipped prep — concrete needs grinding or acid-etch to CSP-2 profile and a moisture test under 3 lb/1,000 sq ft/24 hr.

Water-based or 100% solids epoxy?

100% solids builds full thickness in fewer coats and outlasts water-based — but has a short pot life; work fast.

Last verified: — prices reflect current national averages. See our methodology.

Estimates are for planning. Material densities, coverage rates and prices vary by region and supplier — confirm final quantities before ordering, and check local code where structural or electrical work is involved.