Epoxy Calculator

For deep pour castings or river tables, multiply Length (in) × Width (in) × Pour Depth (in) to get total cubic inches. Divide cubic inches by 1.805 to get fluid ounces, or divide cubic inches by 231 to get US gallons. For flat surface coatings (countertops and tabletops), a standard flood coat at 1/16-inch (62.5 mils) thickness covers approximately 25 to 30 square feet per gallon (or 1 fluid ounce per 0.2 square feet).

A 1:1 mix ratio (by volume) is typical for surface bar top, countertop, and art laminating epoxies, which cure quickly in thin layers (1/8 inch or less) with high surface hardness. A 2:1 mix ratio (2 parts resin to 1 part hardener by volume) is formulated for deep pour casting (river tables and silicone molds); it generates lower exothermic heat during reaction, allowing pours up to 2 to 4 inches thick in a single pass without cracking, boiling, or yellowing.

Standard tabletop epoxies create high exothermic heat and must never be poured thicker than 1/8 to 1/4 inch per layer, or they will overheat, smoke, crack, and shrink. Deep pour / casting epoxy formulations can be poured up to 2 inches (and select formulations up to 4 inches) in a single continuous pour, provided the ambient room temperature is maintained between 65°F and 72°F with proper airflow.

Standard 100% solids epoxy floor coatings cover between 100 to 160 square feet per gallon at 10 to 16 mils wet film thickness. High-build primer coats on porous concrete typically yield 150 to 200 sq ft/gal, while intermediate broadcast coats yield 100 to 125 sq ft/gal. Always add 10% to 15% extra volume to account for rough surface profile absorption and roller squeegee loss.

As a rule of thumb, add 1 to 2 grams of metallic mica powder per 16 fluid ounces of mixed epoxy (or 10 to 20 grams per gallon) for an opaque swirling pearlescent finish. For liquid alcohol inks or transparent dye tints, start with just 2 to 5 drops per 8 ounces and increase until the desired translucency is achieved. Never exceed 5% total pigment by weight, or you will disrupt the chemical cross-linking of the polymer cure.