This calculator will automatically determine the value and size of current limiting resistor that you need to drive any light emitting diode
(LED) from any DC voltage source.
Simply enter the Source Voltage, the LED's Forward Voltage and the desired operating current into the boxes and click the Calculate
Resistor Requirements button. The results will be automatically rounded up to the nearest commonly available resistor.
If you are using the LED in a battery powered circuit that will be charged while the LED is connected, be sure to enter the
highest expected charging voltage, NOT the battery voltage!
