Voltage Divider Calculator

By Calxy · Calculation methodology

Calculate a two-resistor divider’s output, input current and resistor dissipation, including an optional resistive output load.

Printed from Calxy · https://www.calxy.net/other/voltage-divider-calculator

Output voltage across lower branch6.0000 V
V

-1000000000 – 1000000000000000

Ω

1e-12 – 1000000000000000

Ω

1e-12 – 1000000000000000

Output voltage across lower branch

6.0000 V

  • Input current0.0006 A
  • Effective lower resistance10,000.0000 Ω
  • R1 power dissipation0.0036 W
  • R2 power dissipation0.0036 W

Ideal DC resistors. A divider is not a regulated supply; loading changes its output. Component tolerance, temperature and ratings need separate consideration.

How this was calculated

Unloaded: Vout = Vin × R2/(R1 + R2).

With a resistive load, replace R2 in the ratio by R2 ∥ Rload.

Formula and method

Unloaded Vout = Vin × R2/(R1 + R2). With a load to ground, replace R2 in the ratio by R2 in parallel with the load.

Worked example

A 12 V source and two 10 kΩ resistors give 6 V unloaded. Adding a 10 kΩ load across the lower resistor reduces output to 4 V.

Frequently asked questions

Can a divider replace a regulated power supply?

A load changes the divider ratio and output. This ideal resistor calculation is not a regulated-supply model and does not select safe component ratings.

Last updated . Results are estimates for informational purposes only.