Voltage Divider Calculator Formula
Understand the math behind the voltage divider calculator. Each variable explained with a worked example.
Formulas Used
Output Voltage
v_out = v_in * r2 / (r1 + r2)Division Ratio
ratio = r2 / (r1 + r2)Variables
| Variable | Description | Default |
|---|---|---|
v_in | Input Voltage(V) | 12 |
r1 | Resistor R1 (top)(Ω) | 10000 |
r2 | Resistor R2 (bottom)(Ω) | 10000 |
How It Works
How a Voltage Divider Works
Two series resistors produce an output voltage that is a fraction of the input.
Formula
V_out = V_in x R2 / (R1 + R2)
The output is accurate only when load impedance is much higher than R2.
Worked Example
Divide 12 V using two equal 10 kohm resistors.
v_in = 12r1 = 10000r2 = 10000
- 01V_out = 12 x 10000 / (10000 + 10000)
- 02V_out = 12 x 0.5 = 6.0 V
Ready to run the numbers?
Open Voltage Divider Calculator