Calculate LED Resistance

LED Resistor Calculator

Single led - Leds in series - Leds in parallel

Voltage drop is usually 1.9~2.1V for AlGaInP, 3.1~3.5 for InGaN and 1.2V for Infrared.
Current is usualy 20mA, for UFO LEDs current is: 30mA for InGaN and 50mA for AlGaInP.
Supply Voltage - depends what you have at disposal. Usuall is 6V or 12V source.

Single led:
Single led with single resistor
Supply Voltage
  VOLTS
Voltage Drop Across LED
  VOLTS
Desired LED Current
  MILLIAMPS



Calculated Limiting Resistor
  OHMS
Nearest higher rated 10% resistor
 
Calculated Resistor Wattage
  WATTS
Safe pick is a resistor with
power rating of
  WATTS

Leds in series:
Several leds in series with one resistor
Supply Voltage
VOLTS
Voltage Drop Across LED
  VOLTS
Desired LED Current
  MILLIAMPS
How many leds connected
 



Calculated Limiting Resistor
  OHMS
Nearest higher rated 10% resistor
 
Calculated Resistor Wattage
  WATTS
Safe pick is a resistor with
power rating of
  WATTS

Leds in parallel:
Several leds connected parallel with one resistor
Supply Voltage
  VOLTS
Voltage Drop Across LED
  VOLTS
Desired LED Current
  MILLIAMPS
How many leds connected
 



Calculated Limiting Resistor
  OHMS
Nearest higher rated 10% resistor
 
Calculated Resistor Wattage
  WATTS
Safe pick is a resistor with
power rating of
  WATTS
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