LED Resistor Calculator

Calculate the required resistor value for LEDs to prevent damage.

LED Resistor Calculator

Enter supply voltage, LED voltage, and current.

Required Resistor: 0.000 Ω
Power Rating: 0.000 W

 

How to Use

  • Enter supply voltage (Vs)
  • Enter LED forward voltage (Vf)
  • Enter LED current (mA)
  • Click CALCULATE

LED Resistor Explanation

Formula: R = (Vs − Vf) / I

Vs: Supply voltage

Vf: LED forward voltage

I: LED current (in Amps)

Power: P = (Vs − Vf) × I

LED Formula Table

Parameter Formula
Resistance R = (Vs − Vf) / I
Power P = (Vs − Vf) × I

FAQs

Why use a resistor with LED?
To limit current and prevent damage.

What happens without resistor?
LED may burn instantly.

Where used?
Arduino, circuits, electronics projects.

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