Example
Input: 9V src, 2V LED, 20mA
Result: 350 Ω
What is LED Resistor Calculator?
Ohm's Law for LEDs.
How it Works
R = (V_source - V_led) / I.
FAQ
Why add resistor?
Limits current to prevent burning.
Standard current?
20mA (0.02A) is typical.
Wattage?
Calculate P=I²R to choose resistor power.
Series LEDs?
Sum the forward voltages.
Parallel?
Not recommended to share one resistor.