LED Driver Calculator

Constant Current LED Driver

LEDs Vf Max. (Vdc):

LEDs Driving Current (mA):

LEDs per String:

Strings in Parallel:

Output Power (W):

Output Current (mA):

Max. Output Voltage (Vdc):

Constant Voltage LED Driver

LED Strip Voltage (Vdc):

Wattage Per Meter (W):

Strip Length (Meters):

Output Power (W):

Output Voltage (Vdc):

What is LED Forward Voltage and Forward Current?

LED Forward Voltage (Vf): The voltage needed to turn on an LED. This value varies by LED type and color and can be found in the LED’s datasheet. For example, red LEDs typically have a Vf of around 2V, while white and blue LEDs usually require 3V or more.

LED Forward Current (If): The amount of current that flows through the LED when operating. The recommended value is also listed in the datasheet. Most standard LEDs operate at 10mA to 30mA, while high-power LEDs may require 350mA, 700mA, or even higher.

Using the correct Vf and If ensures optimal brightness, efficiency, and lifespan while preventing damage.

LED Serial and Parallel Connection

LED Serial Connection (Series): LEDs are connected end-to-end, so the same current flows through all LEDs, but the total voltage adds up. Example: If each LED needs 3V, three LEDs in series require 9V.

LED Parallel Connection: LEDs are connected side by side, so each LED gets the same voltage, but the total current adds up. Example: If each LED draws 20mA, three LEDs in parallel require 60mA.

Choosing the right connection depends on your power source and circuit design.