⚙ Torque Gear Ratio Calculator
Estimate torque multiplication, output RPM, pitch line speed, tooth load, and material safety margin for spur, helical, bevel, planetary, chain, and worm reductions.
📌 Presets
⚙ Gearset Inputs
🎯 Results
📊 Material and Gear Spec Grid
📘 Reference Tables
| Gearset | Typical Ratio | Base Eff. | Best Use |
|---|---|---|---|
| Spur | 1.5:1 to 8:1 | 0.97 | Simple reducers and index drives |
| Helical | 1.5:1 to 6:1 | 0.96 | Quiet conveyors and packaging lines |
| Bevel | 1:1 to 3:1 | 0.94 | Right-angle mixers and transfer drives |
| Planetary | 3:1 to 12:1 | 0.98 | Servo reducers and compact winches |
| Chain | 2:1 to 10:1 | 0.95 | Open drives and gate operators |
| Worm | 10:1 to 40:1 | 0.78 | High reduction and self-lock tendency |
| Application | Target Ratio | Service Factor | Output Goal |
|---|---|---|---|
| Conveyor reducer | 3:1 to 8:1 | 1.15 to 1.30 | Moderate torque, continuous duty |
| Servo positioning | 3:1 to 10:1 | 1.00 to 1.15 | Lower speed with low backlash |
| Gate or opener | 8:1 to 20:1 | 1.30 to 1.50 | High pull force at low RPM |
| Rotary table | 20:1 to 40:1 | 1.15 to 1.30 | High holding torque and slow motion |
| Winch stage | 8:1 to 15:1 | 1.50 to 1.75 | Peak pull with overload reserve |
| Pinion Teeth | Undercut Risk | Ratio Note | Design Hint |
|---|---|---|---|
| 12 to 16 | High | Avoid in standard spur gears | Use profile shift or planetary set |
| 17 to 20 | Moderate | Good starting point for reducers | Common pinion range for 20 degree PA |
| 21 to 28 | Low | Smoother mesh and lower stress | Favors quieter industrial gearsets |
| 29 and up | Very low | Lower ratio jump per tooth step | Useful when tuning exact output RPM |
| Material | Allowable Load | Best Mesh | Typical Duty |
|---|---|---|---|
| Carburized steel | 1900 lbf/in | Spur, helical, planetary | Heavy industrial reducers |
| Through-hardened steel | 1500 lbf/in | Spur, chain, bevel | General industrial drives |
| Ductile iron | 1100 lbf/in | Helical, spur | Moderate shock and noise control |
| Bronze | 900 lbf/in | Worm wheel | Sliding contact and low speed |
| Acetal | 260 lbf/in | Light spur gears | Quiet instruments and feeders |
💡 Ratio Planning Tips
Gears is mechanical component that allow a motor to perform work on a load by transferring motion and force from the motor to the load. Gear ratio allow a person to trade rotational speed for output torque. A higher gear ratio mean that a load will have a slower rotational speed from the motor, but it will have higher output torque.
Because higher output torque mean that there is more force being applied to the load, a person must select a gear ratio that provide enough torque to move the load but does not place excessive force on the gear teeth to the point of failure. If a gear ratio that is too low is chose, the motor wont be able to provide enough torque to move the load. If a gear ratio that is too high is chosen, the speed of the load will be too slow for the requirement of the machine.
How Gears Change Speed and Torque
Torque multiplication are provided to loads through the use of gear ratios. The efficiency of the gears affects the ratio at which the input torque is multiplied. Multiplying the input torque by the gear ratio will provide an output that does not account for efficiency in the gear system; no gear system are 100% efficient.
For instance, a worm gear system may have an efficiency of 78% due to the sliding friction between
