Injection Molding Cycle Time Calculator

Calculate total cycle time and cooling share. This practical tool is an engineering estimate—validate decisions against machine, material, mold, and process data.

Formula and method

Cycle time is the sum of fill, pack, cooling, and mold-motion steps.

Inputs and units

Enter measured or specified values in the displayed units. Keep units consistent; results are rounded for practical planning. This first release uses the displayed engineering units rather than a unit-switcher.

Worked example

2.5 s fill + 5 s pack + 18 s cooling + 5 s mold motion = 30.5 s.

Time physical events, not setpoints

Define the cycle boundary first, then use observed or planned fill, pack/hold, cooling, opening, ejection, closing, and any automation time within that same boundary. A controller setting is not always the elapsed event time.

Use the total for the next decision

Send a credible cycle to Parts Per Hour or Cavity Count. Keep planned downtime and reject rate outside this arithmetic rather than hiding them in a shorter cycle.

Sanity check the cooling share

If cooling dominates the result, it is the first area to investigate—but only against ejection quality, gate freeze-off, dimensions, and warpage criteria.

Interpretation, assumptions, and limitations

This tool provides an estimate for planning and education. It does not replace machine maker limits, material data sheets, mold trials, cavity-pressure data, process validation, or qualified engineering review.

FAQ

Should robot removal be included?

Include it when it lengthens the defined mold-to-mold cycle. State the cycle boundary so capacity calculations use the same definition.