Silicone Mold Volume Calculator

Two calculators in one: how much resin a mold holds, and how much silicone rubber you need to make a mold around your model.

What do you want to know?
Mold cavity

Resin needed

– ml

– fl oz · – g

Per cavity–
With 10% extra–

Next steps

Split the resin or silicone by its mix ratioResin for dice, chess and domino setsConvert ml, ounces and grams

How to use this calculator

  1. Choose "Resin to fill a mold" to find how much resin to mix, or "Silicone to make a mold" to plan a new mold.
  2. For odd shapes, the water method is the most accurate: fill the mold with water and weigh it.
  3. For a new mold, enter the size of your model and the wall thickness you want around it.

How the calculation works

  • Box cavity = length × width × depth; round cavity = 3.1416 × (diameter ÷ 2)² × depth
  • Water method: 1 g of water = 1 ml of volume
  • Mold box = (model length + 2 walls) × (model width + 2 walls) × (model height + 1 wall)
  • Silicone = mold box − model; weight = volume × density

Tips for making silicone molds

  • Glue the model to the base of the mold box so it does not float up when you pour the silicone.
  • Pour silicone in a thin stream from a height into one corner to reduce bubbles.
  • Most mold silicones are mixed by weight. Check your product's ratio before mixing.

Frequently asked questions

How do I find the volume of a silicone mold?

Fill the mold with water, pour the water into a cup on a kitchen scale and read the grams. One gram of water is one milliliter, so 50 g of water means the mold holds about 50 ml of resin.

How much silicone do I need to make a mold?

Build a box around your model with about 1/2 inch of space on each side and above it. The silicone is the box volume minus the model. For a 3 × 3 × 2 inch model that is about 361 ml of silicone.

How thick should the walls of a silicone mold be?

About 1/4 to 1/2 inch (6–12 mm) for most small molds. Thinner walls save silicone but flex more and can bulge when filled with resin.

How much silicone for a dice mold?

Enter the size of the block that holds your dice masters and the box around them. A typical 7-die mold box is about 4 × 3 inches and 1.25 inches deep, which needs roughly 200–250 ml of silicone after subtracting the dice.