BMI Calculator API

GET

Give users accurate BMI calculations and ideal weight ranges.

BMI Calculator computes Body Mass Index along with ideal weight ranges, BMR (Basal Metabolic Rate), TDEE (Total Daily Energy Expenditure), calorie targets, and macronutrient recommendations for fitness and health applications.

Try it — live request, no key required

Request

GETapi.apiverve.com/v1/bmicalculator?weight=180&height=70&unit=imperial

Query parameters

weightnumber

heightnumber

unitstring

Verification

Format

No key required to try it. Get a key to use it in your app.

Example

{
  "status": "ok",
  "error": null,
  "data": {
    "height": "70 inches",
    "weight": "180 lbs",
    "bmi": 25.83,
    "bmiPrime": 1.033,
    "category": "Overweight",
    "risk": "Increased risk",
    "summary": "BMI is above the healthy range. Lifestyle changes may be beneficial.",
    "idealWeightRange": {
      "min": 129,
      "max": 173.5,
      "unit": "lbs"
    },
    "weightToChange": {
      "direction": "lose",
      "amount": 6.5,
      "unit": "lbs"
    },
    "bmr": 1783,
    "tdee": 2763,
    "calorieTargets": {
      "extremeDeficit": 1763,
      "moderateDeficit": 2263,
      "maintain": 2763,
      "moderateSurplus": 3063,
      "bulkSurplus": 3263
    },
    "macros": {
      "lose": {
        "protein": 198,
        "carbs": 198,
        "fat": 75
      },
      "maintain": {
        "protein": 207,
        "carbs": 276,
        "fat": 92
      },
      "gain": {
        "protein": 230,
        "carbs": 345,
        "fat": 85
      }
    }
  }
}

About the BMI Calculator API

BMI Calculator uses the Mifflin-St Jeor equation for accurate BMR calculations and evidence-based activity multipliers for TDEE. It provides actionable data for fitness apps, health trackers, and nutrition planning tools.

What people use it for

Fitness Apps: Calculate BMI, BMR, TDEE and macro targets for users tracking their fitness journey.
Health Tracking: Provide users with their ideal weight range and how much to gain or lose to reach a healthy BMI.
Nutrition Planning: Generate personalized calorie and macronutrient targets for meal planning applications.
Weight Loss Programs: Calculate calorie deficits and protein targets for weight loss applications.

Ways to call it

One endpoint, many ways in — REST with JSON, XML, YAML and CSV, plus GraphQL and an MCP interface for AI agents.

JSON: Default REST response
XML: Markup format
YAML: Human-readable
CSV: Tabular export
GraphQL: Query language
MCP: For AI agents

View all integrations →

Other ways to use BMI Calculator

Same data, same APIVerve account, same credit balance — one key works on all of them.

Give it to an AI agentConnect over MCP and your agent calls it as a native tool — Claude, Cursor, ChatGPT.on VerveKit Google Sheets or ExcelA =VERVE() formula fills a column — no script, no export, recalculates in place.on VerveSheets Ground an agent on itA cited, machine-checkable fact your model can't produce on its own.on VerveContext

Questions.

Common questions about the BMI Calculator API.

Read the docs →

Are BMR, TDEE, and macro targets included on the Free plan?

No. The Free plan returns baseline metrics including BMI, category, and ideal weight range. Advanced fields like BMR, TDEE, calorie deficit or surplus targets, macronutrient breakdowns, and weight-to-change goals require any paid plan, starting with Starter.

Which plan fits 25,000 health calculations a month?

Each calculation costs 2 credits. The Starter plan includes 200,000 credits each billing cycle, which covers up to 100,000 calculations a month, so 25,000 calculations use only a quarter of Starter. On Starter, calls work out to about $0.30 per 1,000 calls. The Free plan includes 100 calls per month.

Does the API support both metric and imperial measurements?

Yes. You can provide measurements in metric units (kilograms and centimeters) or imperial units (pounds and inches) by setting the unit parameter. The API returns formatted outputs and healthy weight ranges in matching units.

What formula is used to calculate BMR and daily calorie expenditure?

BMI Calculator uses the Mifflin-St Jeor equation to compute Basal Metabolic Rate. Total Daily Energy Expenditure is derived from BMR using evidence-based activity multipliers corresponding to the user's activity level.

What happens if a user omits age, gender, or activity level?

The API still calculates standard BMI, the BMI category, and the ideal weight range with just height and weight. However, on paid plans, calculating BMR requires age and gender, and TDEE and calorie targets require activity level, so those metrics are excluded if the inputs are missing.

Request parameters — GET /v1/bmicalculator

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them. Anything not listed here is dropped rather than passed through.

Required

Parameter	Type	Example	Description
`weight`Required	number	`180`	Weight in kg (metric) or lbs (imperial) range 1-inf
`height`Required	number	`70`	Height in cm (metric) or inches (imperial) range 1-inf
`unit`Required	string	`imperial`	Unit system for weight and height `metricimperial`

Optional

Parameter	Type	Example	Description
`age`Optional	number	`30`	Age in years (required for BMR/TDEE calculations) range 1-120
`gender`Optional	string	`male`	Gender (required for BMR/TDEE calculations) `malefemale`
`activityLevel`Optional	string	`moderate`	Activity level (required for TDEE/calorie calculations) `sedentarylightmoderateactiveveryactive`

Example request

1
2

curl "https://api.apiverve.com/v1/bmicalculator?weight=180&height=70&unit=imperial&age=30&gender=male&activityLevel=moderate" \
  -H "x-api-key: YOUR_API_KEY"

Authentication

Send your key in the x-api-key header. That is the only auth step — no token exchange, and no per-endpoint scope to configure.

Header	When	Value
`x-api-key`Required	Every request	Your API key. Header names are case-insensitive, so `X-API-Key` is the same header.
`Authorization`Alternate	Instead of the above	`Bearer <key>` — for clients that only expose bearer auth. Resolves to the same account and the same billing.

401 is the only auth verdict

A 401 means the key is missing, invalid or expired. A 403 means the key is valid but not permitted here — blocked by a key restriction or an IP allow-list. Running out of credits is a 429.

Response — GET /v1/bmicalculator

Every APIVerve endpoint returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape.

Sample response

{
  "status": "ok",
  "error": null,
  "data": {
    "height": "70 inches",
    "weight": "180 lbs",
    "bmi": 25.83,
    "bmiPrime": 1.033,
    "category": "Overweight",
    "risk": "Increased risk",
    "summary": "BMI is above the healthy range. Lifestyle changes may be beneficial.",
    "idealWeightRange": {
      "min": 129,
      "max": 173.5,
      "unit": "lbs"
    },
    "weightToChange": {
      "direction": "lose",
      "amount": 6.5,
      "unit": "lbs"
    },
    "bmr": 1783,
    "tdee": 2763,
    "calorieTargets": {
      "extremeDeficit": 1763,
      "moderateDeficit": 2263,
      "maintain": 2763,
      "moderateSurplus": 3063,
      "bulkSurplus": 3263
    },
    "macros": {
      "lose": {
        "protein": 198,
        "carbs": 198,
        "fat": 75
      },
      "maintain": {
        "protein": 207,
        "carbs": 276,
        "fat": 92
      },
      "gain": {
        "protein": 230,
        "carbs": 345,
        "fat": 85
      }
    }
  }
}

Response fields

Paths are relative to data. Premium fields are absent rather than zeroed on plans that do not include them, so check for presence instead of comparing to 0.

Field	Type	Example	Description
`height`	string	`"70 inches"`	Formatted height with unit
`weight`	string	`"180 lbs"`	Formatted weight with unit
`bmi`	number	`25.83`	Calculated Body Mass Index
`bmiPrime`Premium	number	`1.033`	Ratio of BMI to upper normal limit (25). Values <1 are normal weight.
`category`	string	`"Overweight"`	BMI category (Underweight, Normal, Overweight, Obese Class I/II/III)
`risk`Premium	string	`"Increased risk"`	Health risk level based on BMI category
`summary`Premium	string	`"BMI is above the healthy range. Lifestyle changes may be beneficial."`	Brief interpretation of BMI results
`idealWeightRange`	object	`{...}`	Healthy weight range for this height (min, max, unit)
`min`	number	`129`	Lowest weight in the healthy BMI range
`max`	number	`173.5`	Highest weight in the healthy BMI range
`unit`	string	`"lbs"`	Unit the ideal weight range is expressed in (lbs or kg)
`weightToChange`Premium	object	`{...}`	Weight to lose or gain to reach normal BMI (direction, amount, unit)
`direction`Premium	string	`"lose"`	Whether weight needs to be lost, gained, or maintained
`amount`Premium	number	`6.5`	How much weight to lose or gain to reach the healthy range
`unit`Premium	string	`"lbs"`	Unit the weight change is expressed in (lbs or kg)
`bmr`Premium	number	`1783`	Basal Metabolic Rate - calories burned at rest (requires age, gender)
`tdee`Premium	number	`2763`	Total Daily Energy Expenditure - calories burned per day (requires age, gender, activityLevel)
`calorieTargets`Premium	object	`{...}`	Daily calorie targets for different goals (extremeDeficit, moderateDeficit, maintain, moderateSurplus, bulkSurplus)
`extremeDeficit`Premium	number	`1763`	Daily calories for aggressive weight loss, roughly 1000 below maintenance
`moderateDeficit`Premium	number	`2263`	Daily calories for steady weight loss, roughly 500 below maintenance
`maintain`Premium	number	`2763`	Daily calories to hold current weight, equal to total daily energy expenditure
`moderateSurplus`Premium	number	`3063`	Daily calories for lean weight gain, roughly 300 above maintenance
`bulkSurplus`Premium	number	`3263`	Daily calories for faster weight gain, roughly 500 above maintenance
`macros`Premium	object	`{...}`	Macronutrient targets in grams (protein, carbs, fat) for lose/maintain/gain goals
`lose`Premium	object	`{...}`	Daily macronutrient grams for the weight loss calorie target
`protein`Premium	number	`198`	Grams of protein per day while losing weight
`carbs`Premium	number	`198`	Grams of carbohydrate per day while losing weight
`fat`Premium	number	`75`	Grams of fat per day while losing weight
`maintain`Premium	object	`{...}`	Daily macronutrient grams for the maintenance calorie target
`protein`Premium	number	`207`	Grams of protein per day at maintenance
`carbs`Premium	number	`276`	Grams of carbohydrate per day at maintenance
`fat`Premium	number	`92`	Grams of fat per day at maintenance
`gain`Premium	object	`{...}`	Daily macronutrient grams for the weight gain calorie target
`protein`Premium	number	`230`	Grams of protein per day while gaining weight
`carbs`Premium	number	`345`	Grams of carbohydrate per day while gaining weight
`fat`Premium	number	`85`	Grams of fat per day while gaining weight

Response headers

Every response carries your balance, so your own code always knows where it stands without polling anything. All four are exposed to browsers through CORS.

Header	What it carries
`x-api-remaining-credits`	Credits left in the current cycle
`x-api-credits-used`	Credits spent in the current cycle
`x-api-max-credits`	The allowance for the cycle
`x-api-version`	Version of the endpoint that answered

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change.

Status	Meaning	What to do
`400`	Input was rejected	Read `error`; it names the parameter that has to change.
`401`	Key missing or invalid	Check the header name and the key value.
`403`	Key valid, but not permitted here	A key restriction or an IP allow-list — never a bad key.
`429`	Rate limited, or out of credits	Read `error` to tell them apart, then back off or top up.

What a call costs — 2 credits per call

Credits are shared across every APIVerve API — one balance, one key, one bill. Failed requests never count against it, so a rejected input costs nothing.

Plan	Per month	Credits	BMI Calculator calls	Per 1,000 calls
Free	Free	200	100	Free
Starter	$29.99	200,000	100,000	$0.30
Pro	$99.99	1,000,000	500,000	$0.20
Mega	$299.99	4,000,000	2,000,000	$0.15

Calls are what the credits buy at this API's rate — spend them here, on any of the other APIs, or across both. Nothing is reserved per endpoint.

Compare all pricing tiers →

Call it from cURL — GET /v1/bmicalculator

No SDK to install — this is a plain HTTPS call to /v1/bmicalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

cURL

1
2

curl "https://api.apiverve.com/v1/bmicalculator" \
  -H "x-api-key: YOUR_API_KEY"

Resources

GitHubapiverve/bmicalculator-apiSource, issues and the examples this page is built from.ReferenceBMI Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/bmicalculatornpm apiverve-bmicalculatorPyPI APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Node.js — GET /v1/bmicalculator

Install the Node.js SDK, then call the BMI Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — npm

npm install @apiverve/bmicalculator

Node.js

const res = await fetch("https://api.apiverve.com/v1/bmicalculator", {
  headers: { "x-api-key": "YOUR_API_KEY" },
});
const { data } = await res.json();
console.log(data);

Resources

npm@apiverve/bmicalculatorThe published Node.js client, versioned and signed.GitHubapiverve/bmicalculator-apiSource, issues and the examples this page is built from.ReferenceBMI Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

apiverve-bmicalculatorPyPI APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Python — GET /v1/bmicalculator

Install the Python SDK, then call the BMI Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — PyPI

pip install apiverve-bmicalculator

Python

import requests

res = requests.get(
    "https://api.apiverve.com/v1/bmicalculator",
    headers={"x-api-key": "YOUR_API_KEY"},
)
print(res.json()["data"])

Resources

PyPIapiverve-bmicalculatorThe published Python client, versioned and signed.GitHubapiverve/bmicalculator-apiSource, issues and the examples this page is built from.ReferenceBMI Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/bmicalculatornpm APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from C# / .NET — GET /v1/bmicalculator

Install the C# / .NET SDK, then call the BMI Calculator API with your key. The client wraps the same HTTPS request, so anything it returns is what the endpoint returns.

Install — NuGet

dotnet add package APIVerve.API.BMICalculator

C# / .NET

using var client = new HttpClient();
client.DefaultRequestHeaders.Add("x-api-key", "YOUR_API_KEY");

var json = await client.GetStringAsync("https://api.apiverve.com/v1/bmicalculator");
Console.WriteLine(json);

Resources

NuGetAPIVerve.API.BMICalculatorThe published C# / .NET client, versioned and signed.GitHubapiverve/bmicalculator-apiSource, issues and the examples this page is built from.ReferenceBMI Calculator API docsEvery parameter, every response field, and the errors.ParametersWhat this call acceptsRequired and optional inputs, with example values.

Also published for

@apiverve/bmicalculatornpm apiverve-bmicalculatorPyPI

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Go — GET /v1/bmicalculator

No SDK to install — this is a plain HTTPS call to /v1/bmicalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/bmicalculator", nil)
req.Header.Set("x-api-key", "YOUR_API_KEY")

res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))

Resources

Also published for

@apiverve/bmicalculatornpm apiverve-bmicalculatorPyPI APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from PHP — GET /v1/bmicalculator

No SDK to install — this is a plain HTTPS call to /v1/bmicalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

PHP

$ch = curl_init("https://api.apiverve.com/v1/bmicalculator");
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, ["x-api-key: YOUR_API_KEY"]);

$response = curl_exec($ch);
echo $response;

Resources

Also published for

@apiverve/bmicalculatornpm apiverve-bmicalculatorPyPI APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

Call it from Ruby — GET /v1/bmicalculator

No SDK to install — this is a plain HTTPS call to /v1/bmicalculator with your key in the x-api-key header. Swap in a real key and it runs as-is.

Ruby

require "net/http"

uri = URI("https://api.apiverve.com/v1/bmicalculator")
req = Net::HTTP::Get.new(uri)
req["x-api-key"] = "YOUR_API_KEY"

res = Net::HTTP.start(uri.hostname, uri.port, use_ssl: true) { |h| h.request(req) }
puts res.body

Resources

Also published for

@apiverve/bmicalculatornpm apiverve-bmicalculatorPyPI APIVerve.API.BMICalculatorNuGet

Only the languages APIVerve ships a client for are listed — the rest call the endpoint directly over HTTPS.

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BMI Calculator API

Try it — live request, no key required

About the BMI Calculator API

What people use it for

Ways to call it

Other ways to use BMI Calculator

Questions.

Request parameters — GET /v1/bmicalculator

Required

Optional

Authentication

Response — GET /v1/bmicalculator

Response fields

Response headers

Errors

What a call costs — 2 credits per call

Call it from cURL — GET /v1/bmicalculator

Resources

Also published for

Call it from Node.js — GET /v1/bmicalculator

Resources

Also published for

Call it from Python — GET /v1/bmicalculator

Resources

Also published for

Call it from C# / .NET — GET /v1/bmicalculator

Resources

Also published for

Call it from Go — GET /v1/bmicalculator

Resources

Also published for

Call it from PHP — GET /v1/bmicalculator

Resources

Also published for

Call it from Ruby — GET /v1/bmicalculator

Resources

Also published for

Zero-code embed — one snippet, no backend

Changelog — BMI Calculator API

Health/Wellness

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