Engineering

Gear Ratio Calculator

Find the gear ratio from teeth counts, then compute output RPM, speed change and torque trade-offs for your drivetrain or bike.

Ratio = driven ÷ drive  |  Output RPM = input × (drive ÷ driven)

🔧 Overdrive & reduction

See instantly whether the pair multiplies speed or torque.

📊 RPM output

Enter input speed and read the exact output RPM.

🏋 Bicycle gears

Great for comparing chainring and cassette combinations.

⚡ Torque trade-off

Understand the classic speed-versus-torque inverse relationship.

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