Part Cost Calculator

Scrap rate specifically inflates the resin cost estimate to account for rejected parts and runner regrind that never becomes salable product, but it has no bearing on how fast the machine runs or how the fixed mold tooling cost gets amortized, since those two cost streams are calculated independently from material cost entirely. A process with a high scrap rate pays more per good part in raw material, but that penalty doesn't compound into the machine or mold cost figures shown here.

More cavities multiply parts-per-hour directly, since the same single cycle now produces multiple parts simultaneously rather than one, which spreads the fixed hourly machine rate across more parts and lowers machine cost per part substantially. It also raises annual capacity and parts-per-shift in direct proportion, though a multi-cavity mold typically costs meaningfully more to build in the first place, which is the real tradeoff worth weighing against the per-part machine savings.

A mold's total cost is a fixed, one-time expense regardless of how many parts it ultimately produces, so spreading that identical dollar amount across a much larger expected lifetime quantity dramatically shrinks the amortized cost attributed to any single part. This is exactly why tooling cost tends to dominate total part cost on a short production run and fade into a rounding error on a high-volume program running the same mold for millions of parts.

Parts-per-shift and annual capacity translate your cycle time and cavity count directly into a maximum realistic output rate, assuming the specific shift pattern and uptime this calculator assumes, so comparing that figure against your actual order quantity and deadline is a quick sanity check for whether the tooling and machine combination you're costing out can physically deliver in time. Real-world output also depends on machine uptime, changeovers, and quality issues this calculator doesn't model, so treat the capacity figures as a theoretical ceiling rather than a guaranteed delivery rate.