Gear and pulley ratios
Compare input and output rotation for a pair of gears or pulleys. Tooth count and diameter are alternatives within the selected model; use consistent units.
Your inputs
Start with the example values, then replace them with your own. For tables, keep the vertical bar separators and use a dot for decimals.
This simplified educational calculation has stated assumptions. Do not use it for navigation, engineering safety or other safety-critical decisions.
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Result and workspace
Use the start button to open your result or activity.
How it works
Output rpm = input rpm × input size / output size. External gears reverse direction; an open belt keeps direction.
Worked example
These sample results use the original example inputs in the form. They do not change when you edit your inputs; your own result appears in the workspace.
- Output speed: 60 rpm
- Size ratio: 2
| Direction |
|---|
| Opposite |
Read the result carefully
Results depend on the values and assumptions shown above. Change one input at a time to see its effect. A blank or unavailable result means the data does not support a calculation; it is not zero.