Docs/APIs/BMI Calculator

BMI Calculator

Calculate BMI, BMR, TDEE and nutrition targets

OperationalCredits 1 per callp50 467msHealth/WellnessStar

Overview

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.

Endpoint

One host, one path per API. The block below shows this call in four languages; every one of them is the same HTTP request. Making requests covers the timeouts, retries and parameter rules that apply to all of them. The SDKs wrap the same call in a typed client.

GEThttps://api.apiverve.com/v1/bmicalculator
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_here"
const res = await fetch('https://api.apiverve.com/v1/bmicalculator?weight=180&height=70&unit=imperial&age=30&gender=male&activityLevel=moderate', {
  headers: { 'x-api-key': 'your_api_key_here' },
});

if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);

const { data } = await res.json();
console.log(data);
import requests

res = requests.get(
    "https://api.apiverve.com/v1/bmicalculator?weight=180&height=70&unit=imperial&age=30&gender=male&activityLevel=moderate",
    headers={"x-api-key": "your_api_key_here"},
    timeout=15,
)
res.raise_for_status()

print(res.json()["data"])
package main

import (
	"fmt"
	"io"
	"net/http"
)

func main() {
	req, _ := http.NewRequest("GET", "https://api.apiverve.com/v1/bmicalculator?weight=180&height=70&unit=imperial&age=30&gender=male&activityLevel=moderate", nil)
	req.Header.Set("x-api-key", "your_api_key_here")

	res, err := http.DefaultClient.Do(req)
	if err != nil {
		panic(err)
	}
	defer res.Body.Close()

	out, _ := io.ReadAll(res.Body)
	fmt.Println(string(out))
}

Replace your_api_key_here with the key from your dashboard. When the inputs arrive as a list rather than one at a time, batch requests run up to 200 of them through this same API in a single call.

Authentication

Send your key in the x-api-key header. That is the only auth step — there is no token exchange and no per-endpoint scope to configure. Authentication covers creating, rotating and revoking keys.

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.

Parameters

Sent in the query string. Premium parameters are accepted on every plan but only take effect on plans that include them.

ParameterTypeDescription
weightRequirednumberWeight in kg (metric) or lbs (imperial)
range 1–∞
heightRequirednumberHeight in cm (metric) or inches (imperial)
range 1–∞
unitRequiredstringUnit system for weight and height
metricimperial
ageOptionalnumberAge in years (required for BMR/TDEE calculations)
range 1–120
genderOptionalstringGender (required for BMR/TDEE calculations)
malefemale
activityLevelOptionalstringActivity level (required for TDEE/calorie calculations)
sedentarylightmoderateactiveveryactive

Response

Every API returns the same three top-level keys, so one response handler covers your whole integration: status, error and data. Only data changes shape. Response format covers the envelope, the other output formats and how premium fields are withheld.

Sample response
{
  "status": "ok",
  "error": null,
  "data": {
    "height": "170 cm",
    "weight": "70 kg",
    "bmi": 24.221453287197235,
    "risk": "Low risk",
    "summary": "This weight is normal and you are healthy.",
    "recommendation": "A BMI between 18.5 and 24.9 falls within the 'normal' weight range according to the World Health Organization. This range is associated with the lowest health risk for conditions such as heart disease, diabetes, and certain cancers. However, it's important to note that BMI is not a perfect measure as it does not account for muscle mass, bone density, overall body composition, and racial and sex differences. Therefore, while it's a useful starting point, it should not be the only measure of one's health."
  }
}

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.

FieldTypeExampleDescription
heightstring"170 cm"Formatted height with unit
weightstring"70 kg"Formatted weight with unit
bminumber24.221453287197235Calculated Body Mass Index
riskPremiumstring"Low risk"Health risk level based on BMI category
summaryPremiumstring"This weight is normal and you are healthy."Brief interpretation of BMI results
recommendationstring"A BMI between 18.5 and 24.9 falls within the 'normal' weight range according to the World Health Organization. This range is associated with the lowest health risk for conditions such as heart disease, diabetes, and certain cancers. However, it's important to note that BMI is not a perfect measure as it does not account for muscle mass, bone density, overall body composition, and racial and sex differences. Therefore, while it's a useful starting point, it should not be the only measure of one's health."

Errors

Read the HTTP status first, then error for the specific reason. The body names the parameter that has to change. Error handling covers the full status list and which of them are worth retrying.

StatusMeaningWhat to do
400Input was rejectedRead error; it names the parameter.
401Key missing or invalidCheck the header name and the key value.
403Key valid, but not permittedA key restriction or IP allow-list; see key scoping.
429Rate limited, or out of creditsRead error to tell them apart; see rate limits.

Use cases

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.

Other ways to use BMI Calculator

Set up BMI Calculator on APIVerve, or reach the same source a different way. Your APIVerve account and credits work on all of them — one key, one balance.

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

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