Epoxy Mixing Ratio Calculator
Enter the total amount of epoxy you need and your product's mix ratio. You will get the exact amount of resin (Part A) and hardener (Part B).
How the calculation works
The total volume is divided in proportion to the ratio:
Part A = total × A ÷ (A + B) and Part B = total × B ÷ (A + B)
For 30 fl oz at 2:1, A + B = 3, so Part A is 30 × 2 ÷ 3 = 20 fl oz and Part B is 30 × 1 ÷ 3 = 10 fl oz.
Common epoxy mix ratios
- 1:1: most table-top and art resins. Easy to measure, equal cups of each part.
- 2:1: many deep pour and casting resins, and some coating systems.
- 3:1: some deep pour resins that need slower, cooler curing.
Need to know how much total epoxy to mix first? Try the river table epoxy calculator.
Always follow the ratio and mixing time on your product's label or data sheet. This tool does not convert between volume and weight ratios.
Frequently asked questions
What does a 2:1 epoxy ratio mean?
A 2:1 ratio means two parts resin (Part A) to one part hardener (Part B) by volume. For 30 fl oz of mixed epoxy, that is 20 fl oz of resin and 10 fl oz of hardener.
Is the ratio by volume or by weight?
Check your product. Many tabletop and deep pour epoxies are mixed by volume (such as 1:1 or 2:1), but some are mixed by weight (such as 100:45). This calculator works by volume; if your resin is by weight, weigh the parts on a scale instead.
What happens if I get the ratio wrong?
Too much or too little hardener can leave the epoxy sticky, soft or cloudy and it may never fully cure. Measure accurately, mix thoroughly for the full time stated on the label, and scrape the sides and bottom of the container.
Can I eyeball a small batch?
It is not recommended. Small errors matter more in small batches. Use marked measuring cups or a scale.