Resin Mix Ratio Converter
Convert between resin and hardener mix ratios by weight and volume.
Supports common epoxy ratios like 1:1, 2:1, 3:1, and 5:1.
Enter a mix ratio and total amount — resin and hardener amounts update instantly.
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:
| System Type | Typical Ratio | Common Brands |
|---|---|---|
| Art resin / casting | 1:1 by volume | ArtResin, Pro Marine |
| Laminating epoxy | 2:1 by weight | West System, TotalBoat |
| Deep pour casting | 2:1 by volume | Alumilite, Stone Coat |
| Industrial epoxy | 3:1 or 5:1 by weight | 3M, Loctite |
| Polyester resin | 1-2% catalyst by weight | Bondo, Evercoat |
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.