Gear Ratio Calculator
Teeth or RPM in → ratio, output speed, and ideal torque factor.
Mode
Gear ratio
3:1
ratio = teeth_out / teeth_in
Output RPM
1000
output = motor / ratio
Torque factor (ideal)
×3
Ideal multiplication ≈ ratio
What is this tool?
Gear ratio is typically driven teeth ÷ driver teeth (or motor RPM ÷ output RPM). Ideal torque scales with the ratio while speed scales inversely. Real gearboxes lose efficiency — this model ignores friction and backlash.
How to use it
- Enter tooth counts or motor/desired RPM.
- Read ratio, output RPM, and ideal torque multiplication.
- Apply efficiency derating for real transmissions.
Related electronics & robotics tools
- Ohm's Law CalculatorSolve for voltage, current, resistance, or power from any two values.
- Resistor Color Code CalculatorDecode 4-band and 5-band resistor colors, or encode a resistance value.
- LED Series Resistor CalculatorFind the series resistor for an LED from supply, Vf, and current.
- Voltage Divider CalculatorCompute Vout from R1/R2, or solve for a resistor given a target Vout.