Advanced LED resistor calculator offers tool for designing your LED circuits and selecting the optimal current-limiting resistor value. Simply fill in the necessary fields below and click “Calculate” to begin.

Unlike most online LED resistor calculators, this one offers user to specify custom resistor value or find alternative resistor values and calculate current (A) and power consumed (W) by LED diode and resistor.

Power supply voltage (V):
LED voltage drop (V):
LED current rating (mA):
Number of LEDs:
Used Resistor (optional): Clear

LED Color	Typical Vf Voltage
Red	1.8 to 2.1
Amber	2 to 2.2
Orange	1.9 to 2.2
Yellow	1.9 to 2.2
Green	2 to 3.1
Blue	3 to 3.7
White	3 to 3.4