Injection Molding worked example

Mold Cavitation with annual part demand of 5,000,000 parts/year: a worked example

Push annual part demand up to 5,000,000 parts/year and the picture changes. This example computes every intermediate figure at that operating point. Use this when deciding how many cavities to cut in a new mold. Balance tooling cost against required production output and available press time.

The inputs for this scenario

  • Annual part demand: 5,000,000 parts/year (raised for this scenario; the documented default is 2,000,000)
  • Available production hours per year: 6,000 hrs/year (unchanged)
  • Cycle time per shot: 25 sec (unchanged)

Working through the calculation

  • Applying the documented formula (Shots per year = Available hours x 3600 / Cycle time) to the inputs above produces each figure below.
  • At this operating point the engine returns 7,500,000,000 cavities for good output capacity, the number this scenario is built around.
  • At this operating point the engine returns 30,000,000,000 cavities for gross capacity.
  • At this operating point the engine returns 22,500,000,000 cavities for uptime loss.
  • At this operating point the engine returns 0 cavities for yield loss.

How this compares with the baseline

  • Against the tool's baseline example, where annual part demand sits at 2,000,000 parts/year and the headline result is 3,000,000,000 cavities, this scenario comes in 150% above the baseline at 7,500,000,000 cavities.
  • It computes the minimum number of mold cavities required to meet annual part demand given your usable press hours and cycle time per shot. The value of this scenario is the size of the gap it exposes: that gap, priced out over a year, is the budget you can justify spending to close it.

Results at a glance

  • Good output capacity: 7,500,000,000 cavities (headline result)
  • Gross capacity: 30,000,000,000 cavities
  • Uptime loss: 22,500,000,000 cavities
  • Yield loss: 0 cavities

Run it with your numbers

  • Every input above is editable in the live Mold Cavitation calculator, which recalculates instantly and can be shared with the inputs intact.

Last reviewed 2026-05-12.