1 LED Resistor Calculator

This calculator will help us  determine the values of resistor, voltage input, LED type and current needed in designing a simple LED circuit.

simple LED circuit

How to use the calculator:
1. Input any 3 known values. Example if  you want to find the resistor
    value, you must input the dc voltage, voltage drop (forward voltage) of
    LED and its needed current. just leave the resistor value blank.
2. Click calculate button to display the answer.
3. Click Reset button to clear values and you can try again.

If you are not sure with the current, just use 20mA . Forward voltage and properties of different type of  LED is listed in LED info. You can visit simple led circuit to know more the basic circuit of LED.

Input DC Voltage (V) :
LED DC Current (mA) :
LED Voltage Drop (V):
Resitor Value (ohms) :