Free Epoxy Calculator — Gallons, Kits & Cost (2026)

How to Use This Calculator

1. 1Measure the length and width of your floor in feet.
2. 2Select 1 coat for a color base or 2 coats for maximum durability.
3. 3Adjust the coverage per gallon if your product specifies a different rate (default is 250 sq ft/gal).
4. 4Click Calculate for gallons, kit count, and cost estimate.

About This Material

Epoxy floor coating is a two-part thermosetting resin (Part A resin + Part B hardener) that cures into a hard, chemical-resistant, glossy surface. It is the most popular garage floor coating and is also used in basements, workshops, commercial kitchens, warehouses, and showrooms. There are three main types of epoxy floor coatings. Water-based epoxy is the most DIY-friendly — it has low odor, easy cleanup, and costs $30 to $50 per gallon kit covering 250 square feet. It provides a good finish but is thinner and less durable than solvent-based or 100% solids options. Solvent-based epoxy is more durable and chemical-resistant, costs $45 to $80 per gallon, and requires adequate ventilation during application. 100% solids epoxy is the professional-grade option — it contains no water or solvents, builds the thickest film in a single coat, and costs $80 to $120 per gallon. It has a very short pot life (15 to 30 minutes) and requires experience to apply. Surface preparation is the most critical step in epoxy application. The concrete must be clean, dry, and profiled (roughened) for the epoxy to bond. A failed moisture test (plastic sheet taped to the floor overnight shows condensation) means the slab needs a moisture vapor barrier before epoxy. Grinding or acid etching creates the surface profile needed for adhesion. New concrete must cure at least 28 days before coating. Most consumer kits include decorative color chips (flakes) that are broadcast into the wet epoxy for a terrazzo-like appearance. A clear topcoat of polyurethane or polyaspartic is applied over the chips for UV resistance and additional durability. Polyaspartic topcoats cure faster (4 to 6 hours vs. 24 hours for epoxy) and resist yellowing from UV exposure. Application temperature must be between 50°F and 90°F with concrete temperature above 55°F. Humidity above 85% can cause blushing (a milky haze) in the cured film. Most two-coat systems are drive-on ready in 3 to 5 days.

Installation Tips

• •Perform a moisture test (tape a 2×2 ft plastic sheet to the floor for 24 hours) before starting — moisture causes epoxy failure.
• •Grind or acid-etch the concrete to create a surface profile — epoxy will not bond to smooth, sealed, or painted concrete.
• •Mix Part A and Part B thoroughly for the full time specified (usually 3 minutes), then let the mixture induct (rest) for the time on the label.
• •Work in sections and keep a wet edge — epoxy self-levels but will show roller marks at seams if one section starts to set.
• •Apply decorative chips within 10 to 15 minutes of rolling each section, while the epoxy is still wet.
• •Allow 12 to 24 hours between coats, and 72 hours before light foot traffic. Wait 5 to 7 days before parking vehicles.

Common Mistakes to Avoid

• ⚠Skipping surface preparation — this is the number one cause of epoxy peeling and flaking. The concrete must be ground or acid-etched.
• ⚠Applying over moisture — trapped moisture underneath causes bubbling and delamination. Always test before coating.
• ⚠Working outside the temperature range — below 50°F the epoxy cures too slowly and may not harden; above 90°F it cures too fast and shows roller marks.
• ⚠Mixing too much product at once — epoxy generates heat as it cures (exothermic reaction). Large batches in a bucket can gel in minutes.
• ⚠Not applying a topcoat — bare epoxy yellows and chalks from UV exposure. A polyurethane or polyaspartic clear coat extends the life significantly.

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