Voltage Divider Calculator

Get output voltage, current and per-resistor power from Vin and two resistors, with formula and ratio breakdown.

3.836735 V
Vout = Vin × R2 / (R1 + R2) = 12 × 4700 / 14,700
Output voltage Vout3.836735 V
Divider ratio0.319728 (31.97% of Vin)
Total resistance14.7 kΩ
Current through divider0.816327 mA
Drop across R18.163265 V
Power in R16.66389 mW
Power in R23.132028 mW
Suggested R2 for 3.3V out3.79 kΩ
R2 = 3.79 kΩ (with R1 = 10 kΩ)

A unloaded divider gives exactly Vout = Vin·R2/(R1+R2) — connecting a load in parallel with R2 lowers Vout (keep load current ≪ divider current, usually divider current ≥ 10× load). Check R1/R2 power ratings: both dissipate I²R continuously.

About Voltage Divider Calculator

Get output voltage, current and per-resistor power from Vin and two resistors, with formula and ratio breakdown.

Voltage Divider Calculator applies the standard formula for this calculation and returns a clean, readable result — no spreadsheet setup or manual working required.

How to Use Voltage Divider Calculator

  1. Enter your numbers in the input fields shown above.
  2. Choose any options (units, rounding, precision) if the tool offers them.
  3. The result updates automatically — no button needed.
  4. Copy the answer or reset the fields to start a new calculation.

Key Features

  • Instant results with a clear, readable output format.
  • Handles decimals, percentages and large numbers cleanly.
  • Fast and private — every calculation runs on your device.

Frequently Asked Questions

What formula does Voltage Divider Calculator use?

Voltage Divider Calculator uses the standard, widely accepted formula for this calculation. Results are rounded only for display, so they are reliable for homework, planning and quick checks.

Is Voltage Divider Calculator free to use?

Yes. Voltage Divider Calculator is completely free with unlimited use — no account, download or payment required.

Is my data uploaded to a server?

No. Voltage Divider Calculator runs entirely in your browser. Your inputs are never sent to our servers or stored anywhere.

Does Voltage Divider Calculator work on mobile?

Yes. The interface is fully responsive and works in any modern browser on Android, iPhone, tablets and desktops.

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