basic

Gear Ratio Speed & Torque Calculator

GR = N_driven/N_drive; ω_out = ω_in/GR; T_out = T_in×GR×η.

Calculates gear ratio, output speed (RPM), and output torque from input speed, input torque, gear teeth counts, and transmission efficiency.

Dr. Helena Ortiz By Dr. Helena Ortiz
Published Last reviewed 1 min read

Inputs

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 = N2/N1; ω_out = ω_in/GR; T_out = T_in×GR×η

In depth

Calculates gear ratio, output speed (RPM), and output torque from input speed, input torque, gear teeth counts, and transmission efficiency.