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LED Current Limiting Resistor Calculator

Using the datasheet of the LED and the voltage used to power the LED, this calculator can determine what resistance in series is required to get your LED functioning and prevent it from burning out.
Circuit Values
Enter the values for your circuit below.
V
The voltage from the power supply.
V
The LED forward voltage drop is usually found in the datasheet for your LED. If you do not have this value, it can usually be determine used a multimeter "diode" setting. This value will likely be between 1.8 and 3.3 volts. A red LED typically has a forward voltage drop of approximately 1.8 volts, increasing to approximately 3.3 volts in a blue LED as the colors move through the spectrum. If necessary, you can estimate using the following values:
Red or Orange2.0 V
Yellow2.1 V
Yellow2.1 V
Green2.2 V
Blue or White3.3 V
mA
The LED forward current is usually found in the datasheet for your LED.
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