Calculate the output voltage, divider current, and power dissipation of a simple resistor voltage divider — one of the most common circuits in electronics.
How it works
- Enter the starting Input Voltage (Vin).
- Specify the resistance for both the top (R1) and bottom (R2) resistors.
- The tool processes the division ratio to output final Vout and dissipated power.
Frequently asked questions
When do I use a voltage divider?
To step down a voltage for signal conditioning, reference voltages, or biasing. Not suitable for powering loads — use a regulator for that.
Why does a load affect the output?
A load in parallel with R2 reduces the effective resistance and pulls the output voltage down. Use a buffer op-amp if the load varies.
How do I choose R1 and R2?
Target Vout = Vin × R2/(R1+R2). Keep total resistance high enough to limit current waste, but low enough to not be affected by load.