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Tools.Town
Free Online Tools for Everyone

BMI Calculator API

Calculate your Body Mass Index and find your healthy weight range — metric and imperial.

Category: Calculators Endpoint: /v1/calculators/bmi Method: GET Auth: API Key

Fast & Accurate

Get precise results instantly.

Easy Integration

Simple REST API with JSON response.

Developer Friendly

Clear docs and SDK examples.

Free to Start

1,000 free requests/month.

Endpoint

All requests should be made to the following endpoint:

GET https://api.tools.town/v1/calculators/bmi

Authentication

This endpoint requires an API Key. Include your API key in the request header.

Authorization: Bearer YOUR_API_KEY
You can get your API key from your dashboard.

Request Parameters

Send a GET request with query parameters.

Parameter Type Required Description Example
weight number Weight must be greater than zero. 70
height number Height must be greater than zero. 175
unit enum The unit parameter. metric

Example Request

curl -G "https://api.tools.town/v1/calculators/bmi" \
  -H "Authorization: Bearer YOUR_API_KEY" \
  --data-urlencode "weight=70" \
  --data-urlencode "height=175" \
  --data-urlencode "unit=metric"

Example Response 200 OK

application/json
{
  "success": true,
  "data": {
    "bmi": "0",
    "category": "string",
    "label": "string",
    "minHealthy": "0",
    "maxHealthy": "0"
  }
}

Error Codes

Code Meaning
400 Bad Request — missing or invalid parameter
401 Unauthorized — API key missing or invalid
429 Rate limit exceeded — free tier: 1,000 requests/month
500 Internal Server Error — try again or contact support