Enter the source voltage (volts), the resistance 1 (ohms), and the resistance 3 (ohms) into the calculator to determine the Thevenin Voltage.

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## Thevenin Voltage Formula

The following formula is used to calculate the Thevenin Voltage.

**Va-b = Vs * R3 / (R1+R3)**

- Where Va-b is the Thevenin Voltage (volts)
- Vs is the source voltage (volts)
- R1 is the resistance 1 (ohms)
- R3 is the resistance 3 (ohms)

## How to Calculate Thevenin Voltage?

The following example problems outline how to calculate the Thevenin Voltage.

**Example Problem #1**

- First, determine the source voltage (volts). In this example, the source voltage (volts) is determined to be 10 .
- Next, determine the resistance 1 (ohms). For this problem, the resistance 1 (ohms) is measured to be 3 .
- Next, determine the resistance 3 (ohms). In this case, the resistance 3 (ohms) is found to be 4.
- Finally, calculate the Thevenin Voltage using the formula above:

Va-b = Vs * R3 / (R1+R3)

Inserting the values from above into the equation gives:

Va-b = 10 * 3 / (3+4)** = 4.28**(volts)

**Example Problem #2**

Using the same method as above, determine the variables required by the equation. For this example problem, these are provided as follows:

source voltage (volts) = 50

resistance 1 (ohms) = 5

resistance 3 (ohms) = 6

Entering these given values into the calculator above yields:

Va-b = 50 * 5 / (5+6) = 22.72** **(volts)