LED resistor calculator

Calculator and formulas for calculating the LED series resistor

Calculate the LED series resistor


LEDs are usually operated via a series resistor. The series resistor must be dimensioned in such a way that the supply voltage and the maximum permissible current are not exceeded. You can calculate the size of the resistor on this page.


LED resistor calculator

 Input
Source voltage V
LED voltage V
LED current
Decimal places
 Results
Series resistor Rv
Resistor Power Pv
LED Schaltung

Legende

\(\displaystyle V_S \) Source voltage

 \(\displaystyle V_D \)  LED voltage

\(\displaystyle I_D \) Maximum LED current

\(\displaystyle R_V \) Serial resistance

\(\displaystyle P_V \) Serial resistance power rating


Formulas for LED series resistor

Serial resistance \(\displaystyle R_v=\frac{V_S - V_D}{I_D}\)
Serial resistance power rating \(\displaystyle P_v=(V_S - V_D) · I_D\)     \(\displaystyle =I_D^2 · R_v\)

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