Epoxy Resin Mixing Calculator

About this calculator

Epoxy resin and hardener must react in a specific mix ratio (by volume or weight, e.g. 2:1 or 1:1 depending on the product) to cure properly — this calculator splits a total quantity into resin = total × a/(a+b) and hardener = total × b/(a+b) for a ratio a:b, so both parts come out in the exact proportion the manufacturer specifies.

Getting the ratio slightly wrong leaves epoxy tacky, cloudy, or permanently soft since the hardener isn't a solvent but a reactive component of the cure — resin artists, tabletop and river-table woodworkers, boat builders sealing hulls, and anyone doing a coating or casting project use this to measure out both parts accurately by volume or scale, especially for large pours where “eyeballing” the ratio easily fails.