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)
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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Disclaimer: This tool is provided as-is for informational and educational purposes only.

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