Voltage Divider Calculator
Calculate the output voltage (Vout) from a two-resistor voltage divider by entering your input voltage, R1, and R2.
Output Voltage (Vout)
—V
How to Use This Calculator
Enter your input voltage (Vin) and the values of both resistors (R1 and R2 in ohms). R1 is the top resistor (connected between Vin and the output node) and R2 is the bottom resistor (connected between the output node and ground). Click Calculate Vout to see the output voltage.
Formula
The voltage divider formula calculates the proportion of input voltage that appears across R2:
Vout = Vin × R2 / (R1 + R2)
Example
Scenario: Step a 12V supply down to approximately 5V
Using R1 = 10 kΩ, R2 = 6.8 kΩ
Vout = 12 × 6800 / (10000 + 6800)
Vout = 12 × 0.405
Vout ≈ 4.86 V
Using R1 = 10 kΩ, R2 = 6.8 kΩ
Vout = 12 × 6800 / (10000 + 6800)
Vout = 12 × 0.405
Vout ≈ 4.86 V