Engineering Tools

LED Resistor Calculator

Find the perfect series resistor for your LED to ensure it lights up brightly without burning out.

Typical Vf: Red (2.0V), Green/Yellow (2.2V), Blue/White (3.3V)
Typical Current: 10mA - 20mA for standard 5mm LEDs.

Source Voltage must be greater than LED Forward Voltage!
Required Resistor
140 Ω
Power Dissipation
0.056 W (Use ≥ 1/8W)