LED Resistance Calculator


Current limiting resistor calculator for LED's

.:Single LED - .:LED's in series - .:LED's in parallel

Some good values to try:

As supply voltage:
 From molex (computer power supply plug)
5, 7 and 12 volts

As LED forward voltages:
 Red and green; 2 volts
 Blue and white; 3.2 - 3.8 volts

.: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


.:LED's in series



Several LED's in series with one resistor
Supply Voltage
  VOLTS
Voltage Drop Across LED
  VOLTS
Desired LED Current
  MILLIAMPS
How many LED's connected?
 



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


.:LED's in parallel



Several LED's connected parallel with one resistor
Supply Voltage
  VOLTS
Voltage Drop Across LED
  VOLTS
Desired LED Current
  MILLIAMPS
How many LED's 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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Disclaimer! I will not take any responsibility for any destroyed or damaged hardware.