LED Resistor Calculator

Calculate the correct resistor value for LEDs. Enter supply voltage, LED forward voltage, and desired current. Supports series and parallel LED configurations.

30.0Kuses

8.7/10(212)

Quick LED Presets

Supply Voltage (V)

LED Forward V

LED Current (mA)

LEDs Count

Configuration

Recommended Resistor

150 ohm

Calculated: 150.0 ohm | Nearest standard: 150 ohm

Actual Current

20.0 mA

Power Dissipation

60 mW

Total LED Vf

2.0V

Min Resistor Rating

1/4W

LED Resistor Formula

R = (Vs - Vf) / I, where Vs is supply voltage, Vf is LED forward voltage, and I is desired current. Always round up to next standard value.

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