LED Series Resistor Value Calculator

Last Updated on March 30, 2024

LED Series Resistor Value Calculator might help you to choose the suitable Resistor Value for you LED implemented in Circuits. For to Find the perfect Value of Series Resistor to the LED you need to put Supply Voltage (V) that is DC Voltage source range you are going to use, LED Forward Voltage (Vf) – refer the Color and Datasheet of your LED, and LED Forward Current (mA) – you can give your desirable current range or refer the datasheet of your LED for exact value.

LED Resistor Calculator

LED Resistor Calculator


Resistor Value: – ohms

Resistor Wattage: – Watts

After Entering all the required Input Values Hit the Calculate Resistor Button and you will get the Resistor Value and Wattage Results. This Calculator is for Single LED and Resistor. This Calculator Works by the following formula.


  • R is the series resistor value.
  • V source is the supply voltage.
  • V LED is the forward voltage drop across the LED.
  • I LED is the desired LED current.

Resistor Wattage (Power P) is Calculated by the following formula

P = I2 * R

Circuit Diagram Representation

LED in a Circuit

LED Color and Typical Forward Voltage (Vf) List, This is for reference only, use LED datasheet for exact Value.

LED Color and their Forward Voltage

Depends on the type of LED packages these forward voltage may vary, so it is better to refer the datasheet of you LED, if you don’t want to fuse it.

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