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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.
Enter the values for your circuit below.
The voltage from the power supply.
LED forward voltage drop
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 Orange
Blue or White
LED forward current
The LED forward current is usually found in the datasheet for your LED.
Note that the information presented in this article is for reference purposes only. Antique Electronic Supply makes no claims, promises, or guarantees about the accuracy, completeness, or adequacy of the contents of this article, and expressly disclaims liability for errors or omissions on the part of the author. No warranty of any kind, implied, expressed, or statutory, including but not limited to the warranties of non-infringement of third party rights, title, merchantability, or fitness for a particular purpose, is given with respect to the contents of this article or its links to other resources.