CNC Machining worked example

Turning Cycle Time at 8.64% approach, retract, and turret allowance: a worked example

Here is what the math looks like when conditions slip. We hold every other input steady and drop approach, retract, and turret allowance to 8.64%, then walk the calculation through step by step. Estimate turning cycle time from axial or facing cut length, feed per minute, and allowance for approach, retract, and turret motion.

The inputs for this scenario

  • turning cut length: 36 in (held at the documented default)
  • turning feed rate: 12 in / min (held at the documented default)
  • approach, retract, and turret 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 turning cycle time = turning cut length รท turning feed rate.
  • estimated turning cycle time works out to 3.26 min at these inputs, and this is the headline figure for the scenario.
  • base turning cycle time works out to 3 min at these inputs.
  • approach, retract, and turret allowance works out to 8.64 % at these inputs.
  • turning feed rate works out to 12 pieces / min at these inputs.

How this compares with the baseline

  • Against the tool's baseline example, where approach, retract, and turret allowance sits at 12% and the headline result is 3.36 min, this scenario comes in 3% below the baseline at 3.26 min.
  • The practical read: the gap between this scenario and the baseline is entirely attributable to approach, retract, and turret allowance, so recovering it is worth quantifying in dollars before considering equipment or staffing changes. It assumes one constant feed and a single combined cut length, so it underestimates parts with many tool changes, threading passes, or large differences between roughing and finishing feeds.

Results at a glance

  • estimated turning cycle time: 3.26 min (headline result)
  • base turning cycle time: 3 min
  • approach, retract, and turret allowance: 8.64 %
  • turning feed rate: 12 pieces / min

Run it with your numbers

  • To rerun this with your own numbers, open the live Turning Cycle Time calculator, set approach, retract, and turret allowance to your actual value, and adjust the remaining inputs to match your operation.

Last reviewed 2026-05-12.