CNC Machining worked example

Tool Change Time Cost with tool changes per production batch of 9 changes: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop tool changes per production batch to 9 changes, then walk the calculation through step by step. Estimate the cost of tool changes from change count, time per change, hourly machine or labor burden, and a conversion factor.

The inputs for this scenario

  • Tool changes per production batch: 9 changes (the input this scenario stresses; the baseline uses 18)
  • Minutes lost per tool change: 4.5 min / change (held at the documented default)
  • Combined machine and labor burden rate: 110 $ / hr (held at the documented default)
  • Minutes-to-hours conversion factor: 0.02 hr / min (held at the documented default)

Working through the calculation

  • The calculation starts from the formula this tool documents: Tool-change time cost = tool changes per batch × minutes per tool change × machine and labor burden × minutes-to-hours conversion.
  • tool-change time cost works out to 74.4 $ at these inputs, and this is the headline figure for the scenario.
  • Base product works out to 4,455 value at these inputs.
  • Multiplier works out to 0.02 x at these inputs.
  • Factor A x B works out to 40.5 value at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where tool changes per production batch sits at 18 changes and the headline result is 149 $, this scenario comes in 50% below the baseline at 74.4 $.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to tool changes per production batch, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It only captures the time burden of the change itself — it ignores the purchase price of the inserts and any scrap produced during re-qualification of the first part after a swap.

Results at a glance

  • tool-change time cost: 74.4 $ (headline result)
  • Base product: 4,455 value
  • Multiplier: 0.02 x
  • Factor A x B: 40.5 value

Run it with your numbers

  • To rerun this with your own numbers, open the live Tool Change Time Cost calculator, set tool changes per production batch to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.