---
title: "Convert between radio frequency and wavelength. Provide either frequency in MHz or wavelength in metres, and get the full set of equivalent values: frequency in MHz and GHz, wavelength in metres, centimetres, millimetres, and feet. Essential for antenna dimensioning, waveguide selection, and quick band identification. The fundamental relationship is lambda = c / f where c is the speed of light (299 792 458 m/s)."
method: POST
path: "/api/wavelength_freq"
tags: ["rf"]
---

# Convert between radio frequency and wavelength. Provide either frequency in MHz or wavelength in metres, and get the full set of equivalent values: frequency in MHz and GHz, wavelength in metres, centimetres, millimetres, and feet. Essential for antenna dimensioning, waveguide selection, and quick band identification. The fundamental relationship is lambda = c / f where c is the speed of light (299 792 458 m/s).

`POST /api/wavelength_freq`

## Request

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

## Request body

- object
  - `freq_mhz` number: Frequency in megahertz (MHz)
  - `wavelength_m` number: Wavelength in metres

## Response `200`

Computed result for wavelength_freq

- object
  - `result` object, required
    - `freq_mhz` number, required: Frequency in megahertz (MHz)
    - `freq_ghz` number, required: Frequency in gigahertz (GHz)
    - `wavelength_m` number, required: Wavelength in metres
    - `wavelength_cm` number, required: Wavelength in centimetres
    - `wavelength_mm` number, required: Wavelength in millimetres
    - `wavelength_ft` number, required: Wavelength in feet
  - `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)