Circuit Parameters
Resistors
Enter input voltage and resistor values to calculate
More Information
What is a Voltage Divider?
A voltage divider is one of the most fundamental circuits in electronics. It consists of resistors connected in series, with output voltages taken from the junctions between them. This circuit is used extensively in electronics for level shifting, biasing, and signal attenuation.
For a voltage divider with n resistors (R₁, R₂, ..., Rₙ) in series:
The voltage at each node is calculated by subtracting the voltage drop across the cumulative resistance above that node from the input voltage. For a two-resistor divider, this simplifies to:
When ground is placed at a different position, all node voltages are adjusted relative to the ground reference point. Nodes above ground will have positive voltages, and nodes below ground will have negative voltages.
Key Characteristics
Linear Relationship
The output voltage is directly proportional to the input voltage. If you double the input, the output doubles.
Resistor Ratio
The voltage at each node depends on the ratio of cumulative resistances, not just the absolute values. This calculator supports any number of resistors in series.
Ground Reference
By placing ground at different positions, you can create positive and negative voltages relative to the reference point.
Practical Applications
Voltage dividers are used in many applications:
- Sensor interfacing - scaling sensor outputs to match ADC input ranges
- Biasing circuits - setting DC operating points in amplifiers
- Level shifting - converting between different voltage levels
- Potentiometers - variable voltage dividers for volume controls and sensors
- Reference voltages - creating stable reference voltages from power supplies
- Signal attenuation - reducing signal amplitudes in audio and RF circuits
- Multi-tap voltage dividers - providing multiple voltage levels from a single source (this calculator supports any number of resistors for multi-tap designs)
Important Considerations
Load Effects
When a load is connected to any output node, it forms a parallel resistance with the resistors below that node, changing the effective divider ratio. For accurate results, the load resistance should be much larger than the equivalent resistance seen at that node (typically 10x or more). This applies to voltage dividers with any number of resistors.
- Power dissipation - resistors must be rated for the power they will dissipate
- Temperature stability - resistor values change with temperature, affecting accuracy
- Tolerance - resistor tolerances directly affect output voltage accuracy
- Frequency response - at high frequencies, parasitic capacitance can affect performance