Epoxy Resin Ratio Calculator
Free toolEnter the total volume you need (or your mold's dimensions) and the mix ratio to see exactly how much resin and hardener to measure out.
Resin and hardener needed
How to use it
- Enter the length, width and depth of the mould, or the volume you need directly.
- Choose your resin's mix ratio: 1:1, 2:1, 3:1, 4:1 or a custom one.
- Add a wastage margin and read the millilitres of resin and hardener.
What it works out and how
The mould volume in cubic centimetres equals the millilitres of mix needed. The wastage margin is added to that figure and the total is split between resin and hardener according to the parts of the ratio: at 2:1, two thirds is resin and one third hardener. A 20 × 10 × 2 cm mould needs 400 ml, or 440 ml with a 10% margin.
Frequently asked questions
Is the ratio by volume or by weight?
It depends on the manufacturer and the two are not interchangeable, since resin and hardener have different densities. Follow your product's data sheet.
What happens if I get the ratio wrong?
The piece stays tacky or soft and never fully cures. Adding extra hardener does not speed up curing, it ruins it.
Why add a margin?
Some of the mix stays in the cup and on the stirring stick, and porous wood soaks up resin. 10% is usually enough.