Does the allowance replace a separate rapids estimate?

No. It is one percentage on top of cutting time. Keep rapid and positioning moves out of the toolpath length unless you price them inside the allowance.

Why is the estimate higher than length divided by feed?

That division gives the ideal cut. Real paths add approach, retract, and in-cut variation, and the allowance covers them, so the estimate lands closer to the clock.

What allowance suits a finish pass with many corners?

Start between 5 and 15 percent, watch the first part on the machine, then correct the allowance from the measured cycle time.

What does a negative gap to target mean?

The estimate lands under the target cycle time you entered, so the pass has time to spare before it pressures the schedule.

CNC Machining calculator

Milling Cycle Time Calculator

Get the cutting time for a milling pass before it runs. The estimate divides toolpath length by feed rate, then adds an allowance for approach, retract, and in-cut variation.

What this calculator does

Estimated milling cycle time from toolpath length, cutting feed rate, and an allowance for approach, retract, and cut variation.

Formula used

Estimated milling cycle time = toolpath length ÷ feed rate × (1 + allowance ÷ 100)
Base milling cycle time = toolpath length ÷ feed rate
Allowance added time = base cycle time × allowance ÷ 100
Gap to target = estimated cycle time minus target cycle time

Inputs explained

Toolpath Length: Cutting travel from the CAM toolpath, rapids excluded.
Cutting Feed Rate: Programmed cutting feed for this milling pass.
Approach and Retract Allowance: Allowance for approach, retract, positioning, and in-cut variation.
Target Cycle Time: Cycle time the pass must beat to hold the schedule.

How to use the result

Best suited to quoting a milling pass from CAM paths, comparing cycle estimates across programs.
It ignores acceleration, corner slowdowns, and feed changes between roughing and finishing passes. Tool changes, probing, and load or unload time are not part of the estimate.

Current U.S. benchmarks

The producer price index for steel mill products stands at 381.162 (BLS, Aug 2026), up 23.4% from a year earlier. Quotes priced off last quarter's material cost miss this move.
The U.S. has 17,154 machine shops establishments employing about 223,303 workers (Census County Business Patterns, 2023).

Common questions

Does the allowance replace a separate rapids estimate? No. It is one percentage on top of cutting time. Keep rapid and positioning moves out of the toolpath length unless you price them inside the allowance.
Why is the estimate higher than length divided by feed? That division gives the ideal cut. Real paths add approach, retract, and in-cut variation, and the allowance covers them, so the estimate lands closer to the clock.
What allowance suits a finish pass with many corners? Start between 5 and 15 percent, watch the first part on the machine, then correct the allowance from the measured cycle time.
What does a negative gap to target mean? The estimate lands under the target cycle time you entered, so the pass has time to spare before it pressures the schedule.

Related guides

The Milling Cycle Time Reduction Playbook

Last reviewed 2026-10-01.