Silicone Mould Calculator
Work out how much silicone you need
Enter your part's size, mould type and complexity below for an instant silicone volume and weight estimate, kit recommendation, and a list of the extras most mould making projects need.
Choosing your mould type
Open-pour block mould
Your part sits in a mould box and silicone is poured around it. Simple to set up, uses more silicone than a tight-fitting mould.
Two-part block mould
The mould is split into two halves with a parting line and registration keys — needed for parts with undercuts on more than one side.
Brush-on mould
Silicone is brushed on in coats to build a thin shell, then supported by a rigid mother mould. Uses much less silicone for large parts.
Common questions
What if I don't know my part's exact volume?
Leave the part volume field blank and we'll estimate it from your length, width and height — this assumes a fairly typical fill factor, so it's a safe estimate rather than an exact figure.
Which mould type should I choose?
Simple parts with one open face suit an open-pour block mould. Parts with undercuts on multiple sides usually need a two-part mould. Very large or one-off parts are often cheaper to brush-on.
Do I need a mother mould for a brush-on mould?
Yes — a brush-on silicone shell is flexible and needs a rigid support (plaster bandage or fibreglass) to hold its shape while curing and in use.
Can you make the mould for me instead?
Yes. Use our Mould Making Hub to send your STL and project details for a quote.
Need help? Use our Mould Making Hub and send us your STL for a quote.
Tell us about your part and upload your file — we'll come back with a mould design quote.
Go to the Mould Making Hub