TheCircuitDogCircuit Fundamentals
Voltage Divider Calculator
Find the output of a two-resistor divider. Add an optional load resistance to estimate how the load pulls the output down.
Enter the values above and select Calculate result.
Formula
Vout = Vin × Rbottom / (Rtop + Rbottom)
Worked example
With Vin = 12 V and equal 10 kΩ resistors, the unloaded output is 6 V. A finite load lowers the effective bottom resistance and therefore Vout.
Engineering notes
Resistor tolerances, startup timing, input leakage and load impedance matter. Divider outputs are not regulated power supplies.
Always compare calculated values with the actual component datasheet, tolerance stack-up, operating temperature and circuit conditions before applying them to hardware.