Best Epoxy Resin Calculator

Measure only the void (river channel), not the whole table. Multiply length × width × pour depth to get the cubic volume. Most river channels aren't 100% open — wood edges intrude — so a void fill of 80–90% is typical. This calculator handles that automatically.

Deep pours over 1.5″ generate excessive heat (exotherm). Plan for multiple thin pours of 1/2″–1″ to avoid cracking or yellowing.

A 2:1 ratio means 2 parts resin (Part A) to 1 part hardener (Part B) by volume. For every 2 oz of resin you add 1 oz of hardener — total batch = 3 oz.

A 1:1 ratio is simpler: equal volumes of resin and hardener, common for casting and tabletop resins. Always follow your product's datasheet — wrong ratios prevent curing.

For a standard 1/16″ (62 mil) floor coating: approximately 0.8–1.0 fl oz per sq ft per coat. Porous concrete can consume 20–50% more on the first (seal) coat.

For thin art/table coatings at 1/8″: ~1.6 oz/sq ft. Use the floor coating calculator above for exact figures based on your thickness and surface condition.

1 fluid ounce = 1.805 cubic inches. So: cubic inches ÷ 1.805 = fluid ounces.

Example: a 6″ × 6″ × 2″ mold = 72 cubic inches = 72 ÷ 1.805 = ~39.9 fl oz of epoxy needed.

Epoxy always sticks to your mixing container, coating the sides and bottom. You also lose material to drips, bubbles popped off the surface, and spreading waste. A 10% buffer is a minimum for clean projects; 15–20% is safer for first-time pours.

Entry-level casting resin: ~$0.80–$1.50/oz. Mid-range tabletop/river: $1.50–$3/oz. High-performance UV-resistant or marine-grade: $3–$6/oz. Buying in larger kits (gallon+) dramatically reduces cost per ounce.

Most standard resins: max 1/4″ (6mm) per pour before exothermic heat becomes a risk. Deep-pour/casting resins designed for thick pours can handle 1″–4″ in a single pour due to slower curing chemistry. Always check your product's maximum recommended pour depth.