Injection Molding worked example

Injection Molding Cycle Time at 8.64% non-productive time allowance: a worked example

This worked example runs the injection molding cycle time numbers for a tougher week than the baseline: 8.64% non-productive time allowance instead of the typical 12%. Estimate total injection molding cycle time from shot count, press cycling rate, and non-productive time allowance.

The inputs for this scenario

  • Total shots required: 500 shots (held at the documented default)
  • Press cycling rate: 3 shots / min (held at the documented default)
  • Non-productive time allowance: 8.64 % (the input this scenario stresses; the baseline uses 12)

Working through the calculation

  • The calculation starts from the formula this tool documents: Base run time = Total shots required / Press cycling rate.
  • Total molding run time (with allowance) works out to 181 sec at these inputs, and this is the headline figure for the scenario.
  • Net press run time works out to 167 sec at these inputs.
  • Non-productive time added works out to 8.64 % at these inputs.
  • Press cycling rate used works out to 3 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where non-productive time allowance sits at 12% and the headline result is 187 sec, this scenario comes in 3% below the baseline at 181 sec.
  • Use it when scheduling a molding run, costing press time, or loading presses across multiple tools. A result at this level usually justifies acting on the stressed input before touching anything else, because every other figure in the table is downstream of it.

Results at a glance

  • Total molding run time (with allowance): 181 sec (headline result)
  • Net press run time: 167 sec
  • Non-productive time added: 8.64 %
  • Press cycling rate used: 3 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Injection Molding Cycle Time calculator, set non-productive time allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.