Resin Calculator

Work out how much epoxy or casting resin a mould needs from its dimensions, then split the total into part A and part B by your mixing ratio. Calculates in your browser.

Mixing ratio is by volume, check your resin's label, some are 1:1.

Total mixed resin

-

In fluid ounces-
Mould volume-
Part A (resin)-
Part B (hardener)-

Show the math

volume (mL) = length × width × depth  ·  1 cm³ = 1 mL

We add your waste allowance, then split the total by your mixing ratio:

part A = total × A ÷ (A + B)  ·  part B = total × B ÷ (A + B)

Always measure parts A and B by the exact ratio on your resin's instructions, guessing ruins the cure. Mix only what you can pour before it sets, work in a ventilated space, and wear gloves; uncured epoxy is a skin and respiratory irritant.

What this does

A resin calculator works out how much epoxy or casting resin a mould needs from its dimensions, then splits the total into part A and part B by your mixing ratio.

How to use it

  1. Enter the mould length, width, and depth.
  2. Set a waste allowance.
  3. Enter your mix ratio.
  4. Read the total and each part.

How it works

Resin cures correctly only at the exact ratio on its label. For a 2:1 mix that is two-thirds resin and one-third hardener by volume.

volume (mL) = length × width × depth; 1 cm³ = 1 mL

Understanding your result

Resin cures correctly only at the exact ratio printed on its label, so the part A and part B split is the number that matters most, not a rough eyeball. Mix a little extra to cover what clings to the cup and stir stick, measure by the method your brand specifies (volume or weight), and pour in thin layers for deep moulds to avoid overheating.

Example

A 10 × 10 × 2 cm mould holds about 200 mL of resin.

Sources & methodology

Last updated .

Frequently asked questions

How is the volume found?

Length × width × depth gives the volume in cubic centimetres, and 1 cm³ equals 1 mL of liquid resin. We add your waste allowance for cups and drips.

How does the ratio split work?

Resin is mixed by a fixed ratio of part A (resin) to part B (hardener). We divide the total by your ratio, for 2:1, that is two-thirds resin and one-third hardener by volume.

Why measure so carefully?

Epoxy only cures correctly at the exact ratio on its label. Too much hardener stays sticky; too little never fully sets. Measure precisely and mix thoroughly.

Do you store anything?

No, everything is calculated locally in your browser.