Resin Mix Ratio Converter

Epoxy resin and similar two-part systems require precise mixing of resin and hardener in a specific ratio. Getting the ratio wrong can result in a sticky, uncured, or brittle final product.

How mix ratios work: A mix ratio describes the proportion of resin to hardener. For example, a 2:1 ratio by volume means you use 2 parts resin for every 1 part hardener. If you measure 100 ml of resin, you need 50 ml of hardener.

Volume vs weight ratios: Many resin systems specify ratios by weight, not volume, because resin and hardener often have different densities. A 2:1 ratio by weight is NOT the same as 2:1 by volume unless both components have the same density. Always check the manufacturer’s instructions to confirm whether the ratio is by weight or volume.

Common epoxy mix ratios:

Calculating amounts from a ratio: Given a total desired amount and a mix ratio of A:B:

• Resin amount = Total x A / (A + B)
• Hardener amount = Total x B / (A + B)

For example, for 150 ml total at a 2:1 ratio:

• Resin = 150 x 2 / 3 = 100 ml
• Hardener = 150 x 1 / 3 = 50 ml

Important mixing tips:

• Always measure precisely. Even small errors in ratio can prevent proper curing.
• Mix thoroughly for at least 2-3 minutes, scraping the sides and bottom of the container.
• Temperature affects cure time. Warmer temperatures accelerate curing, while cooler temperatures slow it down.
• Working time (pot life) is the time you have to pour and manipulate the mixed resin before it starts to thicken.
• For large pours, mix in smaller batches to avoid overheating (exothermic reaction).
• Use a digital scale for weight-based ratios for the most accurate results.