Use the following calculator to calculate the Voltage regulation calculator to calculate voltage regulation precisely. Enter V_{no-load } and V_{full-load} and click on calculate button.

## Voltage regulation calculator

Enter No-Load Voltage | |

Enter Full-Load Voltage | |

Voltage regulation | |

**Read more: Voltage regulation of transformer**

## Steps to use the voltage regulation calculator

- Enter the no-load terminal voltage:
- Let’s assume: 440 V

- Enter the full-load terminal voltage:
- Let’s assume: 550 V

- Click the calculate button. You should get an output of 15.3%

## Definition

Voltage regulation of a transformer can be defined as the change in the magnitude of the secondary voltage of a transformer when the load changes from full load to no load, assuming a constant primary voltage.

**Where,**

- V
_{no-load }is the no-load voltage measured across the secondary terminals - V
_{full-load }is the voltage measured across the secondary terminal at full load.

### Percent voltage regulation

Normally, voltage regulation is expressed as either per – unit or percentage of load voltage

## Example problem:

Consider a three-phase, star-connected alternator that is fully loaded at 0.8 lagging power factor. Below are the terminal voltage details:

- The line voltage measured at the alternator terminals at full load: 440 V
- The terminal voltage at no load with speed and field excitation being maintained constant: 520 V

Let’s calculate its voltage regulation for this alternator using the formula given above:

**Solution:**

- Voltage regulation = (520 – 440)/520 = 0.153
- Percent voltage regulation = 0.1818 * 100 = 15.3%

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