The mix ratio on your resin's label tells you how to split the total into Part A (resin) and Part B (hardener). The charts below do the split for common batch sizes, and the steps cover how to measure and mix so the epoxy cures fully.
Direct Answer
Use the ratio printed on your product. At 1:1, mix equal parts resin and hardener; at 2:1, two parts resin to one part hardener; at 3:1, three parts to one. A 16 fl oz batch is 8 + 8 oz at 1:1, 10.7 + 5.3 oz at 2:1, and 12 + 4 oz at 3:1. If the label gives the ratio by weight, weigh both parts instead of using cups.
Takeaways
| Total mixed | 1:1 | 2:1 | 3:1 |
|---|---|---|---|
| 4 fl oz | 2 + 2 oz | 2.7 + 1.3 oz | 3 + 1 oz |
| 8 fl oz | 4 + 4 oz | 5.3 + 2.7 oz | 6 + 2 oz |
| 16 fl oz | 8 + 8 oz | 10.7 + 5.3 oz | 12 + 4 oz |
| 32 fl oz | 16 + 16 oz | 21.3 + 10.7 oz | 24 + 8 oz |
| 64 fl oz | 32 + 32 oz | 42.7 + 21.3 oz | 48 + 16 oz |
| 128 fl oz (1 gal) | 64 + 64 oz | 85.3 + 42.7 oz | 96 + 32 oz |
Each cell is resin (Part A) + hardener (Part B), by volume. Rounded to 0.1 fl oz.
| Total mixed | 1:1 | 2:1 | 3:1 |
|---|---|---|---|
| 100 ml | 50 + 50 ml | 66.7 + 33.3 ml | 75 + 25 ml |
| 250 ml | 125 + 125 ml | 166.7 + 83.3 ml | 187.5 + 62.5 ml |
| 500 ml | 250 + 250 ml | 333.3 + 166.7 ml | 375 + 125 ml |
| 1,000 ml | 500 + 500 ml | 666.7 + 333.3 ml | 750 + 250 ml |
Each cell is resin (Part A) + hardener (Part B), by volume. Rounded to 0.1 ml.
Resin and hardener usually have different densities, so a ratio by weight (for example 100:45) does not match the same numbers by volume. Use measuring cups only when the label gives a volume ratio; for a weight ratio, use a digital scale.
When to measure with cups and when you need a scale.
An off-ratio mix may not cure, or may cure with weaker properties. Typical signs are soft or sticky spots, areas that never cure, cracking, and excess shrinkage. Changing the amount of hardener does not fix a pour; follow the label ratio.
The calculator's ratio selector refers to the ratio on your product label. An unconfirmed ratio stays unconfirmed. Weight mode does not split a geometric volume into component masses: you need the manufacturer's weight quantities or appropriate component density data. Purchasing a full matched kit is also different from mixing the full kit at once.
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Reviewed · Calculation notes and corrections