LED Resistor Calculator

Calculate the required series resistor for LEDs based on supply voltage, forward voltage, and current

LED Presets

Red (2V / 20mA)Green (2.1V / 20mA)Blue (3.2V / 20mA)White (3.3V / 20mA)Yellow (2.1V / 20mA)IR (940nm) (1.2V / 50mA)UV (405nm) (3.4V / 20mA)

Input Parameters

Supply Voltage Vs (V)

LED Forward Voltage Vf (V)

LED Forward Current If (mA)

LEDs in Series

R = (Vs - Vf × n) / If

Results

Calculated Value

150.0 Ω

Recommended E24 (Nearest)

150.0 Ω

Actual current: 20.0 mA

Resistor power: 60.0 mW