The Energy Efficiency Factor Calculator helps you measure how effectively a system converts input energy into useful output. Whether you’re managing an appliance, motor, industrial process, or building, this tool provides a simple way to understand the proportion of energy that actually goes into productive use. This understanding is essential for reducing waste, saving costs, and improving performance.
This calculator belongs to the Energy and Efficiency Calculators category. It supports engineers, technicians, and energy auditors in tracking performance across mechanical, electrical, or thermal systems.
Formula of Energy Efficiency Factor Calculator
Energy Efficiency Factor (EEF) Formula
EEF = Useful Energy Output / Total Energy Input
Detailed Breakdown:
- Useful Energy Output: This is the energy that performs the intended work (like motion, heating, or lighting). You can measure it in joules, kilowatt-hours (kWh), BTUs, or other units.
- Total Energy Input: This includes all the energy supplied to the system, including what gets lost as heat, vibration, noise, etc.
Both values must use the same unit to ensure the calculation is accurate.
Result
The result is a decimal or percentage. For example:
- 0.75 or 75% means 75% of the input energy became useful output.
- 0.40 or 40% indicates low efficiency, where 60% of energy was wasted.
Reference Table for Common Systems
| System Type | Useful Output | Total Input | EEF (%) |
|---|---|---|---|
| Electric Motor | 720 W | 800 W | 90.0 |
| Incandescent Bulb | 60 W (light) | 100 W | 60.0 |
| Industrial Furnace | 3000 kWh | 5000 kWh | 60.0 |
| Gasoline Car Engine | 700 J | 2000 J | 35.0 |
This table helps you quickly evaluate and compare system performance without doing full calculations every time.
Example of Energy Efficiency Factor Calculator
Scenario:
An industrial pump uses 1,200 kWh of energy in a day. Out of this, only 900 kWh results in actual pumping work. The rest is lost due to heat, friction, and motor inefficiencies.
EEF = Useful Output / Total Input
EEF = 900 / 1200 = 0.75
That means the energy efficiency factor is 75%, which is quite good for mechanical systems.
Most Common FAQs
It means the system converts more input energy into useful output, making it more cost-effective and environmentally friendly.
Yes. As long as both input and output are in the same energy unit (like joules, kWh, or BTUs), the calculator works for all types of energy.
For electrical systems, anything above 85% is excellent. Mechanical or thermal systems may have lower typical values (30–70%) depending on design and application.