Calculation of Current Limiting Resistor Value for LED Light Emitting Diode

Single LED circuit
Note: Different manufacturers and different colors have different voltage drops.

Red: 2.0-2.2v Yellow: 1.8-2.0v

White: 3.0-4v Blue: 3.0-4v

Green: 2.0-2.2v 3.0-3.2v The above is for reference only
Single led with single resistor
Supply voltage V
LED voltage drop V
Required LED current mA
Calculate current limiting resistor Ω
Nearest standard resistor  
Calculate resistor power W
Safe resistor power W

LED series circuit
Supply voltage V
LED voltage drop V
Required LED current mA
Number of connected LEDs  


Calculate current limiting resistor Ω
Nearest standard resistor
Calculate resistor power W
Safe resistor power W

LED parallel circuit
Supply voltage V
LED voltage drop V
Required LED current
 mA
Number of connected LEDs
  
Calculate current limiting resistor Ω
Nearest standard resistor  
Calculate the resistor power W
Safe resistor power W

Calculation of current limiting resistor value for LED light emitting diodes