Calculate
Voltage divider output
Divider: find R2 for a target voltage
LED series resistor
Input voltage (V)
R1, top (ohms)
R2, bottom (ohms)
Target output (V)
Load across R2 (ohms, optional)
Leave empty if the output drives almost nothing, such as a microcontroller input.
Supply voltage (V)
LED color
Infrared (1.4 V)
Red (2.0 V)
Orange or yellow (2.1 V)
Green (2.2 V)
Blue or white (3.2 V)
Other (enter below)
Forward voltage (V)
LED current (mA)
LEDs in series
Calculator by
Engineer Underground
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