Thickness is the number that decides how far a gallon of epoxy goes. Find the typical thickness for your job first, then read across to see how many square feet one gallon covers at that thickness.
Direct Answer
Epoxy thickness depends on the job: garage floor coatings go on at about 10 to 20 mils per coat (0.25 to 0.5 mm), a tabletop flood coat self-levels at about 1/8 inch (3 mm) per pour, and deep-pour casting resin goes in at 1/2 inch to 2 inches per layer, depending on the product. Coverage drops as thickness rises: one gallon covers about 160 sq ft at 10 mils but only about 12.8 sq ft at 1/8 inch.
Takeaways
These are common planning ranges. The product data sheet always wins, especially for floor coatings and deep-pour resins with a stated maximum pour depth.
| Application | Typical thickness per coat | Metric | Notes |
|---|---|---|---|
| Seal coat on wood | Thin brushed coat, 1/32 in or less | Under 0.8 mm | Seals pores and edges so the flood coat does not bubble or drain. |
| Garage floor coating (100% solids) | 10-20 mils | 0.25-0.5 mm | Usually 2 coats. Water-based kits build less film per coat. |
| Tabletop or bar top flood coat | About 1/8 in | About 3 mm | Most tabletop epoxies self-level near 1/8 in per pour. |
| Countertop coating | 1/16-1/8 in per coat | 1.5-3 mm | Budget extra for edges, drips, and a second coat. |
| Deep pour or river table | 1/2-2 in per pour | 13-50 mm | Maximum depth per layer is product-specific. |
Water-based kits, flake base coats, self-leveling slurry and mortar in mils and mm, with wet vs dry film.
Raw coverage for one US gallon of 100% solids epoxy with no waste. For metric, 1 liter covers 1 m² at 1 mm.
| Thickness | Inches | Millimeters | Sq ft per gallon |
|---|---|---|---|
| 5 mils | 0.005 | 0.13 | 321 |
| 10 mils | 0.010 | 0.25 | 160 |
| 20 mils | 0.020 | 0.51 | 80 |
| 1/32 inch | 0.031 | 0.79 | 51 |
| 1/16 inch | 0.063 | 1.59 | 25.7 |
| 1/8 inch | 0.125 | 3.18 | 12.8 |
| 1/4 inch | 0.250 | 6.35 | 6.4 |
| 1/2 inch | 0.500 | 12.7 | 3.2 |
| 1 inch | 1.000 | 25.4 | 1.6 |
The wet-film geometry chart and a manufacturer's spread rate answer different questions. One m² at one mm is one liter of wet material before waste. A product label may specify a spread rate for a particular coat, surface and solids content. Choose one model for that product; do not treat both as separate amounts to add together. For fluid ounces per square foot at 1/8 and 1/16 in, see how much epoxy per square foot; for floor systems in mils and mm, see epoxy floor thickness.
Related Pages
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Reviewed · Calculation notes and corrections