Gear Ratio Calculator
Calculate gear ratio, output RPM, and torque multiplier from driving and driven gear tooth counts and input speed.
How to Use the Gear Ratio Calculator
- Enter the number of teeth on the driving (input) gear.
- Enter the number of teeth on the driven (output) gear.
- Enter the input shaft speed in RPM.
Schnellreferenz
| Von | Nach |
|---|---|
| 1:1 | Direct drive |
| 2:1 | Speed halved, torque doubled |
| 3.5:1 | Typical 1st gear |
| 0.7:1 | Overdrive |
| 4.1:1 | Final drive (performance) |
| 2.73:1 | Final drive (economy) |
Anwendungsfälle
- •Designing gearboxes for motors and engines.
- •Calculating bicycle or vehicle drivetrain ratios.
- •Sizing gears for conveyor and industrial machinery.
Formel
Gear Ratio = Driven Teeth / Driving Teeth. Output RPM = Input RPM / Gear Ratio. Torque Multiplier = Gear Ratio (ignoring losses).
Häufig gestellte Fragen
What does gear ratio mean?
Gear ratio is the ratio of the number of teeth on the driven gear to the driving gear. A ratio >1 reduces speed and multiplies torque; <1 increases speed.
Does this account for efficiency losses?
No. This calculator assumes 100% mechanical efficiency. Real gears typically have 95–99% efficiency per mesh.
Is this calculator free?
Yes, all OhMyCalc calculators are completely free to use.