Toolnoza

ENGINEERING TOOL

Gear Ratio RPM Calculator

Calculate output RPM and torque for one external gear pair from tooth counts and efficiency.

Gear Ratio RPM Calculator

FREE ONLINE TOOL

Transmission ratio

3

Output speed

500 RPM

Output torque

28.5 N·m

One external gear mesh reverses rotation.

Formula and assumptions

i = z2/z1; n2 = n1/i; T2 = T1 × i × η

One external gear mesh reverses direction; displayed RPM is its magnitude. Whole positive tooth counts. Excludes planetary trains, differential gearing, tooth strength and bearing loads.

Technical reference: KHK — Gear dimensions and speed ratios

STEP BY STEP

How to use gear ratio rpm calculator

  1. Check the input units and assumptions.
  2. Review the result and example.

IN PRACTICE

Example

20 → 60 teeth, 1500 RPM, 10 N·m, 95%: 500 RPM; 28.5 N·m.

GOOD TO KNOW

Which model does this calculator use?

One external gear mesh reverses direction; displayed RPM is its magnitude. Whole positive tooth counts. Excludes planetary trains, differential gearing, tooth strength and bearing loads.

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