What does each cast actually cost?
Material cost per piece, the mold's share of every unit, and how many you have to sell before the mold has paid for itself. Free, no card, nothing to upload.
The line everyone leaves out
Almost every "what should I charge" calculation starts and ends with the material. That is the cheap half. A silicone mold that cost you 30 and survives 50 pours is adding 0.60 to every single piece, which on a tealight is more than the wax in it. On a short run it is frequently the largest line in your unit cost, and it is invisible unless you write it down.
This is also why mold life matters more than mold price. A mold that costs twice as much and lasts three times as long is cheaper per piece. Change the pour count above and watch what happens: the difference between 20 casts and 100 is usually bigger than the difference between two silicone brands.
How long a mold really lasts
- Wax and soap: gentle. A good tin-cure mold can pass 100 pours, platinum-cure more.
- Resin: harsh. The exotherm and the release agents both attack silicone, so 20 to 50 casts is realistic and the surface goes dull before it fails outright.
- Plaster: moderate, but it is unforgiving about trapped moisture. See the plaster cracking guide.
- Concrete: abrasive and strongly alkaline. Expect the low end, and expect the surface finish to go first.
- Printed molds, cast into directly rather than via silicone, last differently again: they do not tear, they lose detail and eventually crack. The decision guide covers which to use.
What this does not count
Materials and the mold. That is all. Your time, packaging, shipping, listing fees and payment processing are all real costs and none of them are in the figure above. A number that ignores them is a floor, not a price. If you are selling, work out your hourly rate separately and add it: on hand-poured work it is usually the biggest line of the lot, and it is the one most often valued at zero.
Note also that selling what you cast commercially needs the right licence. Free use is personal only; Pro and Founder grant commercial rights, and the licence page spells out exactly what each covers.
Questions
How do I find the volume of my mold cavity?
Fill it with water and weigh the water. One gram is one millilitre closely enough for costing. If the mold is already designed in Meshcast, the generator reports the cast volume directly and you can skip the guessing.
Why is my per-piece cost higher than I expected?
Almost always the mold share, and almost always because the pour count is optimistic. Try halving it and see whether the business still works. A cost model that only survives at 100 pours is a fragile one.
Can I lower the mold's share?
Two ways. Make the mold cheaper, mostly by using less silicone, which is what a hugging shell does compared with a block mold. Or make it last longer: platinum-cure silicone, a proper release agent, and not demolding while the cast is still warm. The release agents guide covers the third.
How much silicone will the mold need?
That is the silicone calculator, which gives you volume, weight and cost, and the box dimensions to print.