How do you calculate gear cutting cycle time?

Divide the number of gear blanks by your verified cutting rate to get base machine time, then multiply by one plus the setup and inspection allowance. For 180 blanks at 24 gears/hr with an 18% allowance: 7.5 hr base x 1.18 = 8.85 hr total.

Why add a setup and inspection allowance?

The raw cutting math ignores fixturing the blank, dialing in the hob, cutting the first article, and gauging tooth profile or runout. An 18% allowance turns an optimistic 7.5-hour cut into a realistic 8.85 hours, which is what you should actually block on the machine.

What is a good cutting rate for gear hobbing?

It varies wildly with module, material, and number of teeth. Small fine-pitch spur gears can run 30-60 per hour; large hardened or multi-start worm gears may be well under one per hour. The point is to use a rate you have verified on this exact part, not a catalog figure.

Gear cutting cycle time vs base cutting time, what is the difference?

Base cutting time is just blanks divided by rate (7.5 hr here) and represents spindle-in-cut time only. Cycle time (8.85 hr) is the schedulable number that includes setup and inspection, so always quote the cycle time, not the base.

How can I shorten gear cutting cycle time?

Raise the verified cutting rate with better hob coatings, climb hobbing, or higher feeds where the gear class allows it, and shrink the allowance by standardizing fixtures and using SPC sampling instead of 100% inspection on stable processes.

Does this work for gear shaping and skiving too?

Yes. The model is process-agnostic: plug in the verified parts-per-hour rate for shaping, hobbing, or power skiving and an allowance that reflects that process's setup and gauging burden.

Bearings, Gears & Power Transmission calculator

Gear Cutting Cycle Time Calculator

Gear cutting cycle time tells a gear shop how many machine hours a batch of blanks will actually tie up on a hobbing, shaping, or skiving machine once setup and inspection are folded in. Process planners and CNC schedulers use it to slot jobs into hob and gear-shaper queues, quote lead times, and decide whether a second-shift cut is needed. Because cutting a 180-gear run at 24 gears/hr looks like 7.5 hours on paper but really consumes closer to 8.85 hours after fixturing and first-article checks, the allowance is what keeps the schedule honest. It is the number that determines whether a power-transmission order ships on the promised date.

What this calculator does

Estimate total gear cutting hours from gear blanks, demonstrated cutting rate, and setup or inspection allowance for hobbing, shaping, or skiving work.
a gear shop needs to schedule hobbing, shaping, skiving, or spline cutting work for a defined batch of gear blanks
It computes total gear cutting machine hours for a batch by dividing blanks by the verified cutting rate and inflating that by a setup and inspection allowance.

Formula used

Base cutting time = gear blanks to cut ÷ verified cutting rate
Required gear cutting time = base cutting time × setup and inspection allowance factor

Inputs explained

Gear blanks to cut:
Verified cutting rate:
Setup and inspection allowance:

How to use the result

Use it when scheduling a hobbing or gear-shaping job, quoting cutting lead time, or sizing how much spindle time a power-transmission order will consume.
It assumes one verified rate across the whole batch, so multi-module runs, tool changes mid-batch, or a worn hob that slows the cut will push real time above the estimate.

Current U.S. benchmarks

The U.S. has 21,668 machinery manufacturing establishments employing about 1,086,146 workers (Census County Business Patterns, 2023).

Common questions

How do you calculate gear cutting cycle time? Divide the number of gear blanks by your verified cutting rate to get base machine time, then multiply by one plus the setup and inspection allowance. For 180 blanks at 24 gears/hr with an 18% allowance: 7.5 hr base x 1.18 = 8.85 hr total.
Why add a setup and inspection allowance? The raw cutting math ignores fixturing the blank, dialing in the hob, cutting the first article, and gauging tooth profile or runout. An 18% allowance turns an optimistic 7.5-hour cut into a realistic 8.85 hours, which is what you should actually block on the machine.
What is a good cutting rate for gear hobbing? It varies wildly with module, material, and number of teeth. Small fine-pitch spur gears can run 30-60 per hour; large hardened or multi-start worm gears may be well under one per hour. The point is to use a rate you have verified on this exact part, not a catalog figure.
Gear cutting cycle time vs base cutting time, what is the difference? Base cutting time is just blanks divided by rate (7.5 hr here) and represents spindle-in-cut time only. Cycle time (8.85 hr) is the schedulable number that includes setup and inspection, so always quote the cycle time, not the base.
How can I shorten gear cutting cycle time? Raise the verified cutting rate with better hob coatings, climb hobbing, or higher feeds where the gear class allows it, and shrink the allowance by standardizing fixtures and using SPC sampling instead of 100% inspection on stable processes.

Last reviewed 2026-05-12.