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Resin & hardener mixing ratio calculator

Enter your product’s A:B mixing ratio and its measurement basis to split a desired total, a known component, or compatible unmixed stock.

Resin mixing calculator

The product may specify different A:B ratios by weight and by volume. Never interchange them.

Replace the example ratio with the manufacturer ratio for your product.

Results

Enter the manufacturer ratio and active amounts to see results.

This arithmetic aid does not verify compatibility, cure or safety. In volume mode, totals sum measured component volumes; cured yield may differ.

How to calculate

  1. Choose the ratio basis printed by the manufacturer: weight or volume.
  2. Enter the Part A:Part B ratio, then choose a target total, known A, known B, or available stock.
  3. Select one unit for the active inputs. Review the A and B amounts and follow your product’s mixing instructions.

What this calculator covers

  • Known-total, known-resin and known-hardener arithmetic.
  • Stock-limited usable amounts, remainders and limiting component.
  • Separate weight and volume drafts, with no density conversion.
  • Optional extra mixture only for a desired total.

Worked examples

  • At 2:1 by weight and 300 g total, use 200 g A and 100 g B. A 10% allowance gives 220 g A and 110 g B.
  • At 100:45 by weight and 200 g A, use 90 g B for 290 g total. Starting from 90 g B recovers 200 g A.
  • At 3:2 by volume and 250 mL total, measure 150 mL A and 100 mL B. This says nothing about their masses.
  • At 2:1 with 500 g A and 180 g B available, use 360 g A and 180 g B; 140 g A remains.

Ratio, units and limits

For ratio a:b and total T, A = T × a/(a+b) and B = T × b/(a+b). With known A, B = A × b/a; with known B, A = B × a/b. Ratio parts are not percentages.

For stock A₀ and B₀, scale = min(A₀/a, B₀/b). Multiply each ratio part by scale; subtract the used amount from each stock. The smaller capacity identifies the limiting component.

Weight and volume ratios are separate manufacturer instructions. Weight ounces differ from US and Imperial fluid ounces. Without density information, grams cannot be inferred from milliliters.

An allowance multiplies both nominal components by 1 + percentage/100. It preserves the ratio but does not predict losses. Rounded figures may not sum exactly; calculations use unrounded amounts.

The stock result is the total possible at the specified ratio, not a recommended single batch. Actual mix size, pour depth and handling follow product instructions. Do not change a ratio to alter curing.

Privacy and scope

Inputs are processed in this browser component and are not saved or sent by the calculator. Other page services may make ordinary network requests.

This tool does not validate compatibility, cure, safety or structural performance. Use components of the same approved epoxy system; do not use it for UV resin or polyester catalyst.

Questions about resin mixing

No. A 2:1 ratio means two parts A for every one part B on the selected measurement basis; it is not 2% and 1%.

No. Total mixture is A plus B. For 300 g at 2:1, A is 200 g and B is 100 g.

Choose known Part B. The calculator computes A = B × A ratio part ÷ B ratio part, then adds both parts.

No. Select the manufacturer’s weight ratio for a scale. The weight and volume ratios for one epoxy may differ.

No. One US fluid ounce is 29.5735295625 mL; one Imperial fluid ounce is 28.4130625 mL. A weight ounce is 28.349523125 g.

The stock mode shows each usable amount and its remainder. Zero stock is valid and produces zero mixture.

In known-total mode, it scales both components and the total by the same percentage for planning losses. It does not add to known stock.

It is only the arithmetic total available at the ratio. Follow the product’s limits for how much to mix, handle and pour at once.

Sources

Manufacturer instructions govern your product. These references explain measurement basis and mixing; they are not ratio presets.

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