Epoxy Resin Calculator
Calculate epoxy resin and hardener amounts for common mix ratios. Use the result as a volume estimate and verify the product's actual instructions.
Resin Calculation
Getting Your Resin Mix Right (Or You'll Hate Yourself)
Here's the deal: resin is two parts, and the ratio matters. Get it wrong and you've got a sticky mess that never hardens. This calculator is a volume-planning tool, not a substitute for the manufacturer's instructions. Some products are measured by volume, others by weight, and those are not always interchangeable.
The Three Ratios That Actually Work
- 1:1 Equal Parts: Quick-setting, good for small stuff and repairs. You've got about 5-15 minutes to work.
- 2:1 (2 Resin : 1 Hardener): The standard. Bar tops, river tables, anything big. 20-30 minutes to work with it. Best starting point if you're new.
- 3:1 Extended: For when you need 30-45 minutes of working time. Bigger projects, trickier pours. Requires scales, not eye-balling.
Mix Small or You'll Have a Problem
Resin exotherms—it heats up while curing. Mix a gallon at once and you might hit 200+ degrees. That accelerates cure, can damage your molds, and makes it harder to work with. Batch it. Also: ventilation matters. Fumes are real. Work outside or with serious air flow.
Epoxy Types and What They're Good For
| Type | Working Time | Full Cure | Use This For |
|---|---|---|---|
| Standard (2:1) | 20-30 min | 24-48 hr | Bar tops, tables, jewelry |
| Extended (3:1) | 30-45 min | 48-72 hr | Large pours, outdoors |
| Fast Cure (1:1) | 5-15 min | 12-24 hr | Quick fixes, small work |
| Deep Pour (2:1) | 45-60 min | 3-5 days | River tables, thick pours |
Don't Guess the Volume
Length × Width × Depth (all in inches) ÷ 1,728 = gallons needed. Then add 15% for waste because you'll spill some. Round up when buying—running short halfway through is the worst.
