Enter the initial and final voltage into the calculator to determine the voltage percentage. This calculator helps to understand the percentage change in voltage levels.

Voltage Percentage Formula

The following formula is used to calculate the voltage percentage.

VP = (FV / IV) * 100

Variables:

  • VP is the voltage percentage (%)
  • FV is the final voltage (V)
  • IV is the initial voltage (V)

To calculate the voltage percentage, divide the final voltage by the initial voltage and then multiply by 100 to get the percentage.

What is Voltage Percentage?

Voltage percentage is a way to express the change in voltage as a percentage. It is often used to describe the efficiency of voltage regulators, transformers, and other electrical components that alter voltage levels. A higher voltage percentage indicates a greater change in voltage, which can be critical in applications where precise voltage control is necessary.

How to Calculate Voltage Percentage?

The following steps outline how to calculate the Voltage Percentage.


  1. First, determine the initial voltage (IV) in volts.
  2. Next, determine the final voltage (FV) in volts.
  3. Next, gather the formula from above = VP = (FV / IV) * 100.
  4. Finally, calculate the Voltage Percentage (VP).
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

initial voltage (IV) = 12 V

final voltage (FV) = 9 V