---
title: "Body Fat Calculator"
method: POST
path: "/api/v1/tools/body-fat-calculator"
tags: ["tools"]
---

# Body Fat Calculator

`POST /api/v1/tools/body-fat-calculator`

## Request

- Base URL: `https://toolforte.com`
- URL: `https://toolforte.com/api/v1/tools/body-fat-calculator`
- Auth: HTTP bearer

Body fat percentage from tape measurements using the US Navy method. The Hodgdon and Beckett (1984) circumference formula takes height, neck and waist for men and adds the hip for women, returns the American Council on Exercise category band, and splits a body weight into fat and lean mass when one is given. This is an indication, not medical advice.

## Request body

- object
  - `sex` string
  - `heightCm` integer
  - `neckCm` integer
  - `waistCm` integer
  - `hipCm` integer
  - `weightKg` integer

## Response `200`

Successful result

- object
  - `ok` boolean
  - `data` object
    - `sex` string
    - `bodyFatPercent` number
    - `category` string
    - `fatMassKg` number
    - `leanMassKg` number
    - `formula` string
    - `categories` object[]
      - `id` string
      - `label` string
      - `male` integer[]
      - `female` integer[]
    - `note` string

## Other responses

- `400`: Missing or invalid request fields
- `401`: Invalid or missing API key
- `429`: Monthly plan limit reached

---

[API](https://skmtc.dev/toolforte/apis/toolforte-api.md) · [All operations](https://skmtc.dev/toolforte/apis/toolforte-api/llms.txt) · [OpenAPI document](https://skmtc.dev/toolforte/apis/toolforte-api/revisions/4d814d484dfc?raw)