LED Resistor Calculator
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