Enter the LED resistance (ohms), the LED current (amps), and the source voltage (volts) into the calculator to determine the LED Voltage.

## LED Voltage Formula

The following formula is used to calculate the LED Voltage.

**Vled = Vs – R*I**

- Where Vled is the LED Voltage (Volts)
- R is the LED resistance (ohms)
- I is the LED current (amps)
- Vs is the source voltage (volts)

## How to Calculate LED Voltage?

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

**Example Problem #1**

- First, determine the LED resistance (ohms). In this example, the LED resistance (ohms) is determined to be 16 .
- Next, determine the LED current (amps). For this problem, the LED current (amps) is measured to be 7 .
- Next, determine the source voltage (volts). In this case, the source voltage (volts) is found to be 2.
- Finally, calculate the LED Voltage using the formula above:

Vled = Vs – R*I

Inserting the values from above into the equation gives:

Vled = 17 – 7*2 = 3 (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:

LED resistance (ohms) = 5

LED current (amps) = 4

source voltage (volts) = 1

Entering these given values into the calculator above yields:

Vled = 5 – 4*1 = 1 (Volts)