LED Current Limiter Calculator

Calculate the series resistor needed to limit current for an LED. Free online EE tool.

Supply Voltage (V)

LED Forward Voltage (Vf)

Desired LED Current (I)

Resistor Needed

500.00 Ω

Power: 0.20 W

Resistor Power Dissipation

0.200 W

Use 0.40 W rated resistor minimum

LED Power

0.040 W

R = (V_supply - V_LED) / I_LED = (12.0 - 2.0) / 0.020 = 500.00 Ω