Gear Ratio Calculator
Calculate a simple gear ratio from driven teeth divided by driver teeth.
How to use
- Enter the driver/input gear tooth count.
- Enter the driven/output tooth count and calculate.
Capabilities and scope
The tool models one gear pair using output-teeth/input-teeth.
How it works
gear ratio = outputTeeth/inputTeeth.
Example
20-tooth input and 60-tooth output give ratio 3.
Useful for
- Check reduction ratio of one gear pair
- Estimate ideal output speed ratio
Before you use it
- Compound trains, planetary gears, efficiency, and rotation direction are not modeled.
Frequently asked questions
What does ratio 3 imply for speed?
For an ideal simple pair, output speed magnitude is about one third of input speed.