basic

Gear Ratio and Output Speed from Teeth Count Calculator

GR = T_driven/T_driver; ω_out = ω_in/GR.

Calculates gear ratio GR = T₂/T₁, output RPM = input RPM / GR, output torque = input torque × GR × η, and pitch line velocity for a spur gear pair.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

RPM
N·m

Results

Enter values and click Calculate to see results.
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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

GR = T₂/T₁; N_out = N_in/GR; T_out = T_in×GR×η

In depth

Calculates gear ratio GR = T₂/T₁, output RPM = input RPM / GR, output torque = input torque × GR × η, and pitch line velocity for a spur gear pair.