# Power Transmission Efficiency Calculator

Calculate the overall efficiency of a multi-stage transmission. η_total = η₁·η₂·…·ηₙ. Enter one stage efficiency per line (decimal, e.g. 0.98). Optionally add an input power to get the total loss and per-stage output power.

> Canonical page: https://elysiatools.com/en/tools/power-transmission-efficiency

- **Category:** Math & Numbers

- **Keywords:** transmission efficiency, overall efficiency, multi-stage, gear train, power loss, eta total, cascade efficiency, mechanical engineering

## Overview

The Power Transmission Efficiency Calculator computes the overall efficiency of multi-stage mechanical transmissions, such as gear trains, belt drives, and speed reducers. By entering individual stage efficiencies and an optional input power, you can instantly determine the total cascade efficiency, cumulative power loss, and final output power.

## Inputs

- **Stage Efficiencies (ηᵢ)** (textarea): One efficiency per line (decimal in (0,1\], e.g. 0.98 for 98%). Comma/space separated also accepted.
- **Input Power P_in (W)** (number): Optional. If provided, the total power loss and per-stage output power are computed.
- **Decimal Places** (number)

## When to use

- Designing multi-stage gearboxes, belt drives, or chain drives to evaluate cumulative mechanical losses.
- Estimating the final output power and heat dissipation requirements of a drivetrain under a specific input load.
- Comparing different transmission configurations by analyzing how individual component efficiencies affect the overall system performance.

## How it works

- Enter the efficiency of each transmission stage as a decimal value between 0 and 1 on a new line, or separated by commas or spaces.
- Optionally input the initial power in Watts to calculate the absolute power losses and output power at each stage.
- Adjust the decimal places precision setting and run the calculation to generate the overall efficiency percentage and power metrics.

## Use cases

- Gearbox design analysis to calculate the cumulative efficiency of multiple gear meshes and bearings.
- Industrial conveyor system planning to determine the motor size required after accounting for multi-stage drive losses.
- Automotive drivetrain optimization to evaluate the power delivered to the wheels based on engine output and transmission stages.

## Frequently asked questions

### What format should I use for the stage efficiencies?

Enter them as decimal values between 0 and 1 (for example, 0.98 for 98% efficiency), with one value per line or separated by spaces.

### Can I calculate power loss without entering the input power?

No, you must provide an input power value in Watts to calculate the absolute power loss and final output power.

### How is the overall efficiency calculated?

It is calculated by multiplying the efficiencies of all individual stages together: η_total = η₁ × η₂ × ... × ηₙ.

### What units are used for the input and output power?

The calculator uses Watts (W) for power inputs and outputs.

### Is there a limit to the number of transmission stages I can add?

No, you can enter as many stage efficiencies as your transmission system requires, one per line.

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