---
title: "Calculates output voltage, current draw, and power dissipation for a resistive voltage divider. Given an input voltage Vin and two resistor values R1 (upper) and R2 (lower), computes Vout = Vin * R2 / (R1 + R2), divider current, individual resistor power dissipation, and the division ratio. Essential for biasing circuits, level shifting, ADC input scaling, and feedback networks. Use before trace_width to size traces for divider current, or chain from a power supply output to verify signal levels."
method: POST
path: "/api/voltage_divider"
tags: ["pcb"]
---

# Calculates output voltage, current draw, and power dissipation for a resistive voltage divider. Given an input voltage Vin and two resistor values R1 (upper) and R2 (lower), computes Vout = Vin \* R2 / (R1 + R2), divider current, individual resistor power dissipation, and the division ratio. Essential for biasing circuits, level shifting, ADC input scaling, and feedback networks. Use before trace_width to size traces for divider current, or chain from a power supply output to verify signal levels.

`POST /api/voltage_divider`

## Request

- Base URL: `https://calc.engineer`
- URL: `https://calc.engineer/api/voltage_divider`
- Auth: none declared

## Request body

- object
  - `vin` number, required: Input voltage in volts (V). Must be positive.
  - `r1_ohm` number, required: Upper resistor value in ohms (R1), connected between Vin and Vout node.
  - `r2_ohm` number, required: Lower resistor value in ohms (R2), connected between Vout node and ground.

## Response `200`

Computed result for voltage_divider

- object
  - `result` object, required
    - `vout` number, required: Output voltage in volts at the R1-R2 junction.
    - `current_ma` number, required: Current through the divider in milliamps (mA).
    - `power_r1_mw` number, required: Power dissipated by R1 in milliwatts (mW).
    - `power_r2_mw` number, required: Power dissipated by R2 in milliwatts (mW).
    - `ratio` number, required: Voltage division ratio R2/(R1+R2), dimensionless 0-1.
    - `total_power_mw` number, required: Total power dissipated by the divider in milliwatts (mW).
  - `tool` string, required
  - `version` string, required
  - `computed_at` string, date-time, required
  - `chain` object, required
    - `feeds` unknown[]
      - unknown
    - `accepts_from` unknown[]
      - unknown

## Other responses

- `400`: Validation error or invalid JSON
- `404`: Tool not found

---

[API](https://skmtc.dev/calc/apis/calc-engineer-api.md) · [All operations](https://skmtc.dev/calc/apis/calc-engineer-api/llms.txt) · [OpenAPI document](https://skmtc.dev/calc/apis/calc-engineer-api/revisions/8830480ec488?raw)