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Efficiency Calculator
Calculate the efficiency of your external power supply and check compliance with DoE Level VI, ErP Stage II and CoC Tier 2 requirements.
Our power supply efficiency calculator helps you determine the efficiency of AC/DC adapters, desktop power supplies and other external power supplies. Enter the input and output values to calculate efficiency and compare the results against current energy efficiency standards.
Understanding power supply efficiency is important when selecting an external power supply, as higher efficiency reduces wasted energy, lowers heat generation and can improve overall system reliability.
Whether you are selecting a new power supply or checking an existing design, the calculator provides a quick way to assess performance and identify products that meet the latest requirements.
Looking for a compliant external power supply? Contact our team for help selecting the right solution.
Eps Efficiency Calculator
Try Our EPS Average Efficiency Calculator Tool Today
Your Results
AC-AC External Power Supplies except low voltage EPS & Multiple Voltage output EPS (Basic Voltage)
Average Efficiency %
| Ecodesign 2019/1782 ≥ | EU (CoC) Tier 2 ≥ | DoE Level VI ≥ |
|---|
No Load Condition (W)
| Ecodesign 2019/1782 ≤ | EU (CoC) Tier 2 ≤ | DoE Level VI ≤ |
|---|
AC-AC External Power Supplies (Low Voltage <6V & ≥ 550mA output)
Average Efficiency %
| Ecodesign 2019/1782 ≥ | EU (CoC) Tier 2 ≥ | DoE Level VI ≥ |
|---|
No Load Condition (W)
| Ecodesign 2019/1782 ≤ | EU (CoC) Tier 2 ≤ | DoE Level VI ≤ |
|---|
AC-DC External Power Supplies except low voltage EPS & Multiple Voltage output EPS (Basic Voltage)
Average Efficiency %
| Ecodesign 2019/1782 ≥ | EU (CoC) Tier 2 ≥ | DoE Level VI ≥ |
|---|
No Load Condition (W)
| Ecodesign 2019/1782 ≤ | EU (CoC) Tier 2 ≤ | DoE Level VI ≤ |
|---|
AC/DC External Power Supplies (Low Voltage <6V & ≥ 550mA output)
Average Efficiency %
| Ecodesign 2019/1782 ≥ | EU (CoC) Tier 2 ≥ | DoE Level VI ≥ |
|---|
No Load Condition (W)
| Ecodesign 2019/1782 ≤ | EU (CoC) Tier 2 ≤ | DoE Level VI ≤ |
|---|
Multiple Voltage output External Power Supplies
Average Efficiency %
| Ecodesign 2019/1782 ≥ | EU (CoC) Tier 2 ≥ | DoE Level VI ≥ |
|---|
No Load Condition (W)
| Ecodesign 2019/1782 ≤ | EU (CoC) Tier 2 ≤ | DoE Level VI ≤ |
|---|
Frequently Asked Questions
Find answers to common questions about power supply efficiency, external power supplies and DoE Level VI requirements.
What is an efficiency calculator?
An efficiency calculator helps you determine how effectively an external power supply converts input power into usable output power. Higher efficiency means less wasted energy and lower heat generation.
How do you calculate power supply efficiency?
Power supply efficiency is calculated using the following formula:
Efficiency (%) = Output Power ÷ Input Power × 100
For example, if an external power supply draws 120W from the mains and delivers 108W to the load, the efficiency is 90%.
Why is power supply efficiency important?
Higher efficiency means less wasted energy, lower heat generation and improved reliability. It can also help products meet energy efficiency regulations and reduce operating costs.
Which power supplies can this calculator be used for?
This calculator is suitable for:
- External power supplies
- Plugtop adapters
- Desktop power supplies
- Interchangeable plug power supplies
- Medical power supplies
- USB-C PD chargers
What is considered good power supply efficiency?
Most modern external power supplies operate between 85% and 95% efficiency. Higher efficiency reduces energy losses, lowers heat generation and helps meet current energy regulations.
What is DoE Level VI?
DoE Level VI is an energy efficiency standard for external power supplies. It sets minimum efficiency requirements and limits no-load power consumption to help reduce energy waste.
