What is the Voltage Divider Calculator?
Calculate the output voltage of a two-resistor voltage divider. These physics and science calculators apply standard SI formulas with exact constants (such as g = 9.80665 m/s² and the 2019 SI definitions) for students, engineers and curious minds.
How to use the Voltage Divider Calculator
- Enter your input voltage, your r1, your r2.
- Results update automatically as you type; you can also press Calculate.
- Read the output: output voltage, current.
- Use the 📊 chart to see the result visually, then copy or share it.
Formula and method
Worked example
With input voltage = 12 V, r1 = 10,000 Ω, r2 = 4,700 Ω, the Voltage Divider Calculator returns output voltage: 3.8367 V; current: 0.8163 mA.
Tips for better results
- Convert inputs into SI units first for the cleanest results.
- Idealized formulas ignore friction and air resistance unless stated.
- Use our unit converters to switch between metric and imperial results.
Frequently asked questions
What does the Voltage Divider Calculator do?
Calculate the output voltage of a two-resistor voltage divider.
How is it calculated?
The Voltage Divider Calculator uses this method: Vout = Vin × R2 ÷ (R1 + R2).
Can you show an example?
With input voltage = 12 V, r1 = 10,000 Ω, r2 = 4,700 Ω, the Voltage Divider Calculator returns output voltage: 3.8367 V; current: 0.8163 mA.
Is the Voltage Divider Calculator accurate?
Yes. It uses standard formulas and exact constants, and the results are verified by our automated test suite. Values are displayed to up to 12 significant digits.
Is this tool free and private?
Yes — the Voltage Divider Calculator is completely free with no sign-up, and it runs entirely in your browser, so the values you enter are never uploaded to our servers.
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