Mold Cost Estimator

An injection mold's price is set almost entirely before the first shot is ever run, driven by how the tool is built rather than what it produces. This estimator combines four cost drivers that experienced moldmakers quote from: the mold material (aluminum prototype tooling starts far cheaper than hardened production steel, but wears out orders of magnitude sooner), part geometry complexity (undercuts, thin walls, and multi-material parts all demand more machining and mechanism time), cavity count (adding cavities raises cost, but not linearly — a well-engineered multi-cavity tool spreads fixed design and base costs across more cavities, so cost per cavity falls as cavity count rises), and part size (larger parting-plane area means a physically bigger, more expensive mold base and cavity block). Side actions and lifters, which are mechanisms that free undercuts a straight-pull mold cannot release, add a substantial line item on top of the base estimate, and a hot runner system adds cost but eliminates the material waste of a cold runner system on every cycle.

The amortized cost per part divides total mold cost across the tool's expected shot life, showing how tooling investment gets absorbed into per-unit part cost at your production volume — a mold that looks expensive upfront can still be the cheaper choice once spread across a million parts. The estimator also reports a rough design-and-build lead time (driven by part complexity, side action count, and high cavitation) and an annual maintenance budget (a 2% of build-cost rule of thumb for upkeep like cleaning, polishing, and wear-part replacement) so both the schedule and ongoing ownership cost factor into the tooling decision, not just the upfront price.