volts

(voltage across LED)

ohms


(voltage across
resistor)

amps

LED Protection Resistor Calculator

Enter Component Values Here First &
Then Press "Calculate Protection Resistor"

The Supply/
Battery Voltage

(Vs)

volts
Maximum LED
Voltage

(Vf)

volts
Maximum LED
Current

(If)

milliamps
 



Calculated Protection Resistor
Value =  Ohms


 

 

PREFERRED RESISTOR VALUES
After using the calculator, select the next highest value of resistor from the list below (eg. If calculated resistor = 135 then go up to 150):
22 - 27 - 33 - 47 - 56 - 68 - 100 - 120 - 150 - 180 - 220 - 270 - 330 - 390 - 470 - 560 - 680 - 820 - 1000

LED Protection
Resistor Value

 

See the LED data sheet for maximum Vf voltage & If current values


 

Circuit
Resistance, Voltage and Current values
are calculated from: