Voltage Divider Calculator
Enter Vin and two resistors to get the divided output voltage.
Divide a voltage with two resistors
A voltage divider uses two resistors in series to produce a fraction of the input voltage — one of the most common building blocks in electronics. Enter the input and the two resistor values to get the output.
With 9 V across a 1 kΩ and 2 kΩ divider, the output is 6 V, because R2 takes two thirds of the drop. The tool also reports the current flowing through the pair.
Exact and private
It applies the divider formula directly and computes the loop current too, all in your browser with nothing uploaded.
Frequently Asked Questions
What is the voltage divider formula?
Vout = Vin × R2 / (R1 + R2). The output is the fraction of the input that appears across the second resistor.
Does loading affect the result?
Yes. This gives the unloaded output; connecting a load in parallel with R2 lowers it, so keep the load resistance high relative to R2.
What is it used for?
Scaling a voltage down for a sensor or reference, biasing a transistor, or reading a higher voltage with a lower-range input.
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