LED Resistor Calculator

Resistor Ohm's Law
 
 
To calculate the resistor needed for a simple LED circuit, simply take the voltage drop away from the source voltage then apply Ohm's Law. In Other Words...
Resistor formula for LEDs
Basic LED cicuit
where:Es is the source voltage, measured in volts (V),
Eled is the voltage drop across the LED, measured in volts (V),
Iled is the current through the LED, measured in Amperes (Amps/A), and
R is the resistance, measured in Ohms (Ω).

This calculator is based on the Ohms Law Calculator, but takes into consideration the voltage drop from the LED. To use the calculator, enter any three known values and press "Calculate" to solve for the others.

Voltage Source (Es): Volts (V)
Voltage drop from LED (Eled): Volts (V)
Current through the LED (Iled):
Resitance (R):
Power (P): Watts (W)