Resin Mold Volume Calculator
Measure your mold or weigh the water it holds, and get the volume of resin to mix in millilitres and fluid ounces, plus the weight for kits that measure by grams.
The formula
Worked example. a 10 × 5 × 2 cm mold holds 100 ml; two of them with 10% waste need 220 ml, about 242 g of resin.
How to use it
- Choose the mold shape. Use Rectangle for coasters, trays and blocks, Cylinder for round coasters and pucks, and the water method for any irregular silicone mold.
- Enter the inside dimensions of the mold, or fill the mold with water, weigh the water and enter its weight. Dry the mold completely before pouring resin.
- Enter how many molds you are filling and an allowance for waste. Resin left in the cup and on stir sticks is usually 5–10%.
- Mix the total shown. Split it into part A and part B using the ratio printed on your resin kit, by volume or by weight as the manufacturer specifies.
Questions
Why does my resin kit list a different ratio by weight and by volume?
Part A and part B have different densities, so a 1:1 ratio by volume is not 1:1 by weight. Use whichever the kit specifies and do not mix the two methods.
Is the water method accurate for silicone molds?
Yes. It is the most accurate method for molds with curves, cavities or textured bottoms, because the water fills exactly the space the resin will. Put the empty mold on the scale, zero it, then fill it so you weigh only the water.
Can I pour a deep mold in one go?
Check the maximum pour depth for your resin. Coating and doming resins are usually limited to a few millimetres per layer, while deep pour resins can go several centimetres. Pouring too deep at once can overheat, crack or yellow the piece.