KEVOS® MAKEOS · Gears
Gear Train Ratio, Speed and Torque
What is the overall ratio, output speed and output torque of this gear train?
Overall ratio, output speed, direction, output torque and efficiency of a simple or compound gear train with up to four meshes.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Input speed | rpm | Speed of the first driver. |
| Input torque | N·m | Torque at the first driver. |
| Efficiency per mesh | % | Efficiency of each external spur or helical mesh (typically 97–99% including bearings). |
| Mesh 1 | ||
| Driver teeth | teeth | Teeth on the driver of mesh 1. |
| Driven teeth | teeth | Teeth on the driven gear of mesh 1. |
| Mesh 2 | ||
| Driver teeth | teeth | Teeth on the driver of mesh 2 (on the same shaft as driven gear 1); 0 if not used. |
| Driven teeth | teeth | Teeth on the driven gear of mesh 2. |
| Mesh 3 | ||
| Driver teeth | teeth | Mesh 3 driver, or 0. |
| Driven teeth | teeth | Mesh 3 driven gear, or 0. |
| Mesh 4 | ||
| Driver teeth | teeth | Mesh 4 driver, or 0. |
| Driven teeth | teeth | Mesh 4 driven gear, or 0. |
Method and formulas
- Ratio of each mesh = driven ÷ driver; overall ratio = product of mesh ratios.
- Output speed = input ÷ overall ratio; each external mesh reverses direction.
- Output torque = input torque × ratio × efficiency^(number of meshes).
- Example: 20:60 then 18:54 gives 9:1, 161.11 rpm and 172.87 N·m.
Limitations
- External meshes only; idler gears change direction but not the ratio (enter them as a mesh with equal teeth if needed).
- Example values are illustrations. Replace them with values for your actual task.
Typical uses
- Design a reduction from available gears
- Check output speed of an existing train
- Estimate torque at the output shaft
Who it is for
- Gear designers
- Machinists
- Maintenance engineers
What you get
- Overall ratio
- Output speed and direction
- Output torque
- Overall efficiency
Interpreting the result
- Check each mesh for strength with its own torque, not only the output.
References
- Machinery’s Handbook, 29th edition (Industrial Press, 2012), printed pp. 2122–2160. Topic reference; no source tables or recommended settings are reproduced.
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
