Gearbox Efficiency Calculator

How to Use This Calculator

1. Enter the Input Power (kW) - the total power entering the gearbox from the source.
2. Enter the Output Power (kW) - the power successfully delivered from the gearbox to the load.
3. Enter the Gear Ratio - the ratio of the input shaft speed to the output shaft speed.
4. Optionally, enter a Manual Efficiency (%) if you have pre-calculated or specified value.
5. Click the Calculate button to compute the gearbox efficiency and power loss.

Understanding Gearbox Efficiency

Gearbox efficiency measures how effectively a gearbox transfers power from input to output. It is expressed as a percentage and represents the ratio of output power to input power.

A perfect gearbox would have 100% efficiency, but in reality, some energy is always lost due to:

• Friction between gears and bearings
• Heat generated during operation
• Material deformation
• Air resistance

The efficiency value obtained from this calculator helps in:

• Designing more efficient gearboxes
• Identifying energy losses in existing systems
• Comparing different gearbox designs
• Optimizing maintenance schedules based on performance

Example Calculation

Suppose a gearbox has an input power of 50 kW and an output power of 45 kW:

Efficiency = (45 kW / 50 kW) × 100 = 90%

This means 90% of the input power is successfully transferred to the output, with 5 kW lost to inefficiencies.