Voltage Divider Calculator
Calculate resistor values for voltage dividers. Find standard resistor combinations for your desired output voltage.
Your inputs
Set input voltage, target output, and current limit.
V
V
mA
Your result
Compare suitable resistor pairs and their output.
Recommended Combinations
What is a Voltage Divider?
A voltage divider is a simple circuit that uses two resistors in series to create an output voltage (Vout) that is a fraction of the input voltage (Vin). It's one of the most fundamental circuits in electronics.
Common Applications
- Level shifting for sensors and microcontrollers
- Reference voltage generation
- Biasing in amplifier circuits
- Battery level monitoring
- Signal attenuation
How to Use This Calculator
- Enter your input voltage (Vin)
- Enter your desired output voltage (Vout)
- Optionally, specify a target current for power considerations
- The calculator will show you the best standard resistor combinations
Important Considerations
- The output voltage must always be less than the input voltage
- Lower current means higher resistance and lower power consumption
- Higher current provides better stability but increases power consumption
- Consider resistor tolerance in sensitive applications
- For varying loads, consider using a voltage regulator instead
Formula Used
The voltage divider formula is:
Vout = Vin × (R2 / (R1 + R2))
Where:
- Vout = Output voltage
- Vin = Input voltage
- R1 = Upper resistor
- R2 = Lower resistor