Voltage Divider Calculator
Calculate voltage, resistance, power, and current for voltage divider circuits
Voltage Divider Calculator
Calculate voltage, resistance, power, and current for voltage divider circuits
Instructions:
Enter any 3 values and leave 1 field empty - the calculator will automatically compute the missing value using the voltage divider equation.
Quick Ratios
About Voltage Dividers
A voltage divider is a passive circuit that divides input voltage into smaller output voltages using resistors.
Applications:
- Sensor interfacing
- Reference voltages
- Level shifting
- Biasing circuits
- Feedback networks
Key Formulas
Design Tips
• Use high-value resistors to minimize current
• Consider output impedance for loaded circuits
• Check power ratings of resistors
• Account for component tolerances
• Use precision resistors for accuracy
Voltage Divider Equation
Basic voltage divider equation
Where:
- Vout = Output voltage (voltage across R2)
- Vin = Input voltage (supply voltage)
- R1 = Upper resistor (between Vin and Vout)
- R2 = Lower resistor (between Vout and ground)
Related Formulas:
Current:
Power in R1:
Power in R2:
Total Power:
Features and Options
Automatic Calculation
Input three known values, and the tool determines the fourth instantly.
Unit Switching
Displays results in appropriate units (Ω, kΩ, MΩ) for easy reading.
Power and Current
Shows total circuit current and power dissipation analysis.
Quick Ratios
Preset buttons for common voltage division scenarios.
Common Use Cases
Circuit Protection
Safe voltage levels for sensitive components.
Logic Level Shifting
Interface between different voltage levels.
Reference Voltages
Precise references for ADCs and comparators.
Signal Conditioning
Scaling analog signals for measurement.
How to Use This Calculator
Choose Known Values
Decide which three of the four values (Vin, Vout, R1, R2) you know.
Enter Values
Input the known values. Leave the unknown field empty for automatic calculation.
Get Results
View instant results with detailed calculations and power analysis.
Pro Tips for Better Results
- • Use quick ratio buttons for common scenarios
- • Check power ratings match calculated dissipation
- • Consider resistor tolerance for precision applications
- • Account for loading effects in real circuits
Instructions: Enter any 3 values and leave 1 field empty - the calculator will automatically compute the missing value.
Quick Ratios
About
Calculate voltage divider circuits used in electronics for creating reference voltages, sensor interfaces, and biasing.
Tips
• Use precision resistors for accuracy
• Consider power ratings
• Account for loading effects
Voltage Divider Equation
Basic voltage divider equation
Where:
- Vout = Output voltage (voltage across R2)
- Vin = Input voltage (supply voltage)
- R1 = Upper resistor (between Vin and Vout)
- R2 = Lower resistor (between Vout and ground)
Related Formulas:
Current:
Power in R1:
Power in R2:
Total Power:
Features and Options
Automatic Calculation
Input three known values, and the tool determines the fourth instantly, streamlining circuit design and testing.
Unit Switching
Calculator allows for entry in Ohms, kΩ, or MΩ and displays results in appropriate units for easy reading.
Power and Current
Advanced calculations show total circuit current, power dissipation in resistors, and comprehensive circuit analysis.
Multiple Resistor Support
While this tool focuses on two resistors, the principles can be expanded for more complex voltage divider networks.
Practicality
Useful in scenarios like logic level conversion (e.g., 5V to 3.3V), battery voltage monitoring, and signal conditioning.
Use Cases
Circuit Protection
Designing circuits where a sensor or chip input can't tolerate full supply voltage, providing safe voltage levels for sensitive components.
Logic Level Shifting
Creating interface circuits between devices operating at different voltage levels (e.g., 5V microcontroller to 3.3V sensor).
Reference Voltages
Creating precise reference voltages for analog-to-digital converters (ADCs), comparators, and other analog circuits.
Signal Conditioning
Scaling and conditioning analog signals for measurement, data acquisition, and control systems.
How to Use
Choose Known Values
Decide which three of the four values (Vin, Vout, R1, R2) you know from your circuit requirements or measurements.
Enter Values
Input the known values into their respective fields. Leave the unknown field empty - the calculator will determine this automatically.
Get Results
The tool outputs the missing value instantly, showing detailed calculations including current, power dissipation, and circuit analysis.
Pro Tips:
- • Use the quick ratio buttons (50%, 33%, 25%) for common voltage division scenarios
- • Check power dissipation to ensure resistors can handle the calculated power
- • Consider resistor tolerance when precision is critical
- • For high-precision applications, use 1% or better tolerance resistors