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Epoxy Calculator: Floor Coating or Countertop Pour

Find gallons of epoxy for a floor coating from the coverage on the can, or for a countertop pour from area and thickness. This is a quantity check, not a vinyl box count and not an installed-price page.

ft
ft

Enter the number of coats the product calls for.

sq ft/gal

Default 100 sq ft per gallon per coat is a CalcTheJob editable starting point. Use the figure on the can or PDS.

%

Default 10% is a CalcTheJob planning starting point.

Your estimate

Gallons to buy

4.4gal

4.0 gallons before a 10% waste allowance · 200 sq ft

Area

200 sq ft

Gallons, before waste

4.0 gal

2 coats at 100 sq ft/gal

Floor mode uses the coverage you enter from the kit or can. The 100 sq ft per gallon default is a starting point, not a survey. Countertop gallons are volume: cubic inches of pour (sq ft × 144 × thickness in) ÷ 231 cubic inches per U.S. gallon. This is not a vinyl or laminate box count and not an installed-price page.

Estimates only — confirm with your supplier and local code. First published · Last reviewed by CalcTheJob.

How to use the epoxy calculator

  1. Choose floor coating or countertop pour. The two modes use different assumptions and are not interchangeable.
  2. Enter the length and width. For a floor, also enter coats and the coverage printed on the kit or product data sheet. The default 100 sq ft per gallon per coat is a CalcTheJob starting point, not a survey.
  3. For a countertop pour, enter thickness. The default 1/8 inch is a CalcTheJob editable starting point (enter the thickness your product allows per pour). Gallons are volume in cubic inches divided by 231.

Vinyl and laminate box counts stay on the flooring calculator. A thin underlayment takeoff is on the self-leveling concrete calculator.

Coverage versus pour volume

Floor gallons = area × coats ÷ coverage (sq ft per gallon per coat), then multiplied by 1 + waste. Countertop gallons = area (sq ft) × 144 × thickness (in) ÷ 231, then waste. Do not use one mode’s result as a substitute for the other.

Worked examples

A 20 × 10 ft floor, 200 sq ft, at two coats and 100 sq ft per gallon is 4.0 gallons, or 4.4 gallons with 10% waste. A 24 sq ft countertop pour at 1/8 inch is 24 × 144 × 0.125 ÷ 231 = 1.87 gallons, or 2.06 gallons with 10% waste.

Sources & assumptions

How this calculator gets its numbers. Full method: our methodology.

  • Floor-coating gallons = area × coats ÷ coverage (sq ft per gallon per coat), then × (1 + waste%). The default 100 sq ft per gallon per coat is a CalcTheJob editable starting point, not a survey — enter the figure from the can or PDS.
  • Countertop pour gallons = area (sq ft) × 144 × thickness (in) ÷ 231. The default 1/8 in thickness is a CalcTheJob editable starting point (enter the thickness your product allows per pour). Default 10% waste is a planning starting point.
  • This is a quantity check, not a vinyl or laminate box count and not an installed-price page.

Sources

  1. NIST, Handbook 44 (2026), Appendix C — General Tables of Units of Measurement. Units of Liquid Volume: 4 quarts = 1 gallon = 231 cubic inches, the divisor used for countertop pour volume.

Last reviewed . The coverage printed on the kit or product data sheet wins.

Frequently asked questions

How much epoxy do I need for a 20×10 garage?

At the form’s default 100 sq ft per gallon and two coats, 200 sq ft is 4.0 gallons, or 4.4 gallons with 10% waste. Use the coverage printed on the can when you have it.

How many gallons for a 24 sq ft countertop at 1/8 inch?

Volume is 432 cubic inches, which is 1.87 gallons before waste, or 2.06 gallons with 10% waste.

Is 100 sq ft per gallon a standard coverage?

No. It is a CalcTheJob editable starting point. Enter the figure from the kit or product data sheet.

Does this price an epoxy floor?

No. It is a quantity check only, not an installed-price page and not a vinyl or laminate box count.

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