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Resin Mix Ratio Calculator

A 2 : 1 resin divides the total into three shares — two of resin, one of hardener — so 220 g is 146.7 g of A and 73.3 g of B. The ratio here is by weight. Products routinely print both, a 2 : 1 by volume alongside 100 : 45 by weight, so read the weight figure when you are working on a scale.

Your numbers

Part A

146.7g

Part B

73.3g

Formula

Part A = Resin needed × Ratio part A ÷ (Ratio part A + Ratio part B)

Off-ratio resin does not cure. Extra hardener does not make it harder; it stays tacky, or the heat concentrates and it cracks. Use a scale that reads to 0.1 g, and for small pours under about 20 g mix a little extra and pour from it, because the error weighs more than the resin does. Decanting into a second cup shifts the ratio by whatever stayed in the first.

What to enter

InputDefaultAccepted range
Resin needed (g)Resin needed in total, parts A and B together.2201 and up
Ratio part AThe A side of the mix ratio.20.1 and up
Ratio part BThe B side of the mix ratio.10.1 and up

Step by step

FormulaPart A = Resin needed × Ratio part A ÷ (Ratio part A + Ratio part B)
With the default numbersPart A = 220 × 2 ÷ (2 + 1)
AnswerPart A = 146.7 g

Quick reference table

Results when only Resin needed (g) changes and everything else stays put.

Resin needed (g)Part A (g)Part B (g)
11073.336.7
16511055
220146.773.3
330220110
440293.3146.7

What each result means

ResultAt default values
Part A (g)How much part A to weigh out.146.7
Part B (g)How much part B; eyeballing this is why resin fails to cure.73.3

Common mistakes

Off-ratio resin does not cure. Extra hardener does not make it harder; it stays tacky, or the heat concentrates and it cracks. Use a scale that reads to 0.1 g, and for small pours under about 20 g mix a little extra and pour from it, because the error weighs more than the resin does. Decanting into a second cup shifts the ratio by whatever stayed in the first.

Glossary

Resin needed
Resin needed in total, parts A and B together.
Ratio part A
The A side of the mix ratio.
Ratio part B
The B side of the mix ratio.
Part A
How much part A to weigh out.
Part B
How much part B; eyeballing this is why resin fails to cure.

Frequently asked questions

Q. How is Resin Mix Ratio Calculator calculated?

Part A = Resin needed × Ratio part A ÷ (Ratio part A + Ratio part B) — A 2 : 1 resin divides the total into three shares — two of resin, one of hardener — so 220 g is 146.7 g of A and 73.3 g of B. The ratio here is by weight. Products routinely print both, a 2 : 1 by volume alongside 100 : 45 by weight, so read the weight figure when you are working on a scale.

Q. Can you walk through an example?

With Resin needed 220g, Ratio part A 2, Ratio part B 1, the answer is Part A 146.7g.

Q. What do I need to enter?

Enter Resin needed, Ratio part A, Ratio part B. The result recalculates as you type, and an empty box counts as zero.

Q. How much does the answer move if I change a number?

Changing only Resin needed (g) moves the answer to Resin needed (g) 110 → Part A (g) 73.3 and Resin needed (g) 440 → Part A (g) 293.3. The table below lays out five steps.

Q. How are the numbers rounded?

Money is shown to the nearest whole unit, percentages to one decimal place and everything else to two. What you see is rounded; the calculation itself carries the unrounded value forward.

Q. Anything to watch out for?

Off-ratio resin does not cure. Extra hardener does not make it harder; it stays tacky, or the heat concentrates and it cracks. Use a scale that reads to 0.1 g, and for small pours under about 20 g mix a little extra and pour from it, because the error weighs more than the resin does. Decanting into a second cup shifts the ratio by whatever stayed in the first.

Related calculators

Materials differ in density and absorption. If your label states a figure, use it — the defaults here are only common values.