Voltage Divider Calculator
Work with a total input voltage and a chain of resistors in series. The output shows the voltage drop across each resistor.
Enter a valid total voltage and at least one resistance greater than zero.
Summary--
Free tool
Voltage Divider Calculator
Enter the total voltage and the resistor values in the chain. The calculator distributes the voltage across each section and gives you a reading ready to validate your circuit.
Tools
Calculate the voltage drop across each resistor in the divider
Add as many resistors as you need, choose their units and get the output voltage on each one from a single workspace.
Formula and usage guidance
A classic voltage divider uses resistors in series. Each resistor receives a fraction of the total voltage proportional to its value.
Main relation
- Rtotal = R1 + R2 + ... + Rn
- Vn = Vtotal x (Rn / Rtotal)
What to check
- Make sure all resistors are in series, not in parallel.
- Make sure the load current does not distort the ideal divider.
- Make sure the sum of the voltage drops matches the input voltage.
Quick guide
How to interpret a voltage divider when validating a circuit
A voltage divider distributes the total voltage according to the relative weight of each resistor. It is very useful for analogue inputs, level references, sensor scaling or quick prototype checks.
Quick read
- The total resistance is the sum of all series sections.
- The voltage drop increases as the resistor value gets larger.
- If you connect a load to the output, the real value can deviate from the ideal result.
- Always check units and scales before comparing results.
Resistive sum
The total resistance sets the relative distribution across the chain.
Rtotal = R1 + R2 + ... + RnVoltage on each section
Each resistor receives a fraction of the input voltage.
Vn = Vtotal x (Rn / Rtotal)More tools
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FAQ
Frequently asked questions
A short guide for the most common questions when you size or review a resistive voltage divider.
What does this tool calculate?
It calculates the voltage drop across each resistor in a series chain from the applied total voltage.
Can I add several resistors?
Yes. You can build a chain with as many resistors as you need and the tool will distribute the voltage across all of them.
Does it work if a load is connected?
As an initial reference, yes, but the ideal result changes when the load modifies the total impedance seen at the output.
Is the calculator free?
Yes. You can use it online without registration or downloads.
Next step
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