🏥 Health Calculator API Documentation

📖 Overview

The Health Calculator API provides comprehensive health-related calculations including BMI (Body Mass Index), BMR (Basal Metabolic Rate), Daily Caloric Intake, and Water Intake requirements. All calculations are based on scientifically proven formulas and provide detailed recommendations.

🧮 BMI Calculator

Calculate Body Mass Index with WHO standard categories and health recommendations

🔥 BMR Calculator

Basal Metabolic Rate calculation using the accurate Mifflin-St Jeor equation

🍽️ Daily Intake Calculator

Personalized caloric needs with detailed macronutrient breakdown

💧 Water Intake Calculator

Daily water requirements based on multiple health and environmental factors

🌐 Base URL

https://api.lorwongam.com/api/health-calculator/

🔐 Authentication

No authentication required. This is a public API that can be accessed without any API keys or tokens.

📡 API Endpoints

GET / POST / Unified Health Calculator

The same endpoint handles all four calculators. Pass the calculator name in calculator; the other fields depend on which calculator you choose. Parameters may be supplied via the query string (GET) or as a JSON body (POST) — POSTed keys override query-string keys.

Common Parameters

Parameter	Type	Required	Description
`calculator`	string	Required	One of `bmi`, `bmr`, `intake`, `water`
`unit`	string	Optional	`metric` (default) or `imperial`. For `imperial`, `weight` is treated as pounds and `height` as inches (only relevant for non-water calculators).

Calculator-Specific Parameters

Parameter	Used by	Required	Description
`weight`	all	Required	Weight in kg (or lb if `unit=imperial`)
`height`	bmi, bmr, intake	Required*	Height in cm (or in if `unit=imperial`). Ignored for water.
`age`	bmr, intake, water	Required*	Age in years (1–120)
`gender`	bmr, intake, water	Required*	`male` or `female`
`activity`	bmr, intake, water	Required*	`sedentary`, `light`, `moderate`, `active`, `extra`
`goal`	intake	Required	`maintain`, `lose`, `lose-fast`, `gain`, `gain-fast`
`climate`	water	Required	`cold`, `temperate`, `hot`, `very-hot`
`healthCondition`	water	Required	`normal`, `fever`, `diarrhea`, `kidney`, `heart`, `pregnancy`, `breastfeeding` (note the camelCase spelling)

Example Request — BMI

curl "https://api.lorwongam.com/api/health-calculator/?calculator=bmi&weight=70&height=175"

Example Request — BMR (POST JSON)

curl -X POST "https://api.lorwongam.com/api/health-calculator/" \
  -H "Content-Type: application/json" \
  -d '{
    "calculator": "bmr",
    "weight": 70,
    "height": 175,
    "age": 30,
    "gender": "male",
    "activity": "moderate"
  }'

Example Request — Daily Intake

curl "https://api.lorwongam.com/api/health-calculator/?calculator=intake&weight=70&height=175&age=30&gender=male&activity=moderate&goal=maintain"

Example Request — Water Intake

curl "https://api.lorwongam.com/api/health-calculator/?calculator=water&weight=70&age=30&gender=male&activity=moderate&climate=temperate&healthCondition=normal"

📊 Response Format

Success Response — BMI

{
  "success": true,
  "data": {
    "bmi": 22.86,
    "category": "Normal weight",
    "advice": "Great! Maintain your current lifestyle with a balanced diet and regular exercise."
  },
  "calculator": "bmi",
  "timestamp": "2025-09-09 12:00:00"
}

Success Response — BMR

{
  "success": true,
  "data": {
    "bmr": 1649,
    "detail": "Daily calories needed: 2556",
    "advice": "Your BMR is 1649 calories per day. With your activity level, you need approximately 2556 calories daily to maintain your current weight."
  },
  "calculator": "bmr",
  "timestamp": "2025-09-09 12:00:00"
}

Success Response — Daily Intake

{
  "success": true,
  "data": {
    "calories": 2556,
    "breakdown": "Protein: 112g • Carbs: 367g • Fat: 71g
BMR: 1649 cal • Maintenance: 2556 cal",
    "advice": "To maintain your current weight, aim for 2556 calories per day with balanced nutrition and regular exercise.",
    "macros": {
      "protein": 112,
      "carbs":   367,
      "fat":     71
    }
  },
  "calculator": "intake",
  "timestamp": "2025-09-09 12:00:00"
}

Success Response — Water Intake

{
  "success": true,
  "data": {
    "amount":    "3773ml/day",
    "breakdown": "Total: 3773ml • From drinks: 3018ml • From food: 755ml
Approximately 12.1 glasses (250ml each)",
    "advice":    "Aim for approximately 3773ml (12.1 glasses) of water daily. Spread intake throughout the day...",
    "details": {
      "total":      3773,
      "fromDrinks": 3018,
      "fromFood":   755,
      "glasses":    12.1
    }
  },
  "calculator": "water",
  "timestamp": "2025-09-09 12:00:00"
}

Error Responses

All error responses are JSON with HTTP 400 (or 404 in rare routing edge cases). The shape varies by trigger:

Calculator type missing

{
  "success": false,
  "message": "Calculator type is required",
  "availableCalculators": ["bmi", "bmr", "intake", "water"]
}

Missing required field(s) — message is a comma-joined list, errors is the same list as an array

{
  "success": false,
  "message": "Height is required for bmr calculation, Age is required for bmr calculation, ...",
  "errors":  ["Height is required for bmr calculation", "Age is required for bmr calculation", "..."]
}

Invalid value (out of range / unrealistic)

{
  "success": false,
  "message": "Please check your height and weight values - they seem unrealistic"
}

⚠️ Error Conditions

The API does not return a numeric code field. Errors are identified by the human-readable message string.

Trigger	HTTP	Notes
Missing `calculator`	400	Returns `availableCalculators` to help clients pick
One or more required fields missing for the chosen calculator	400	Returns comma-joined `message` and parallel `errors` array
Age out of range (must be 1–120)	400	`message`: "Age must be between 1 and 120 years"
Unrealistic weight / height	400	`message`: "Please check your height and weight values - they seem unrealistic" (for water: "Please check your weight value - it seems unrealistic")
Negative or zero weight / height (bmi, bmr, intake)	400	`message`: "Weight and height must be positive values"
Negative or zero weight (water)	400	`message`: "Weight must be a positive value"

🚦 Rate Limits

This endpoint is rate-limited per client identity (IP address, or API key when one is supplied): 60 requests per minute. When the budget is exhausted the API responds with HTTP 429 and includes X-RateLimit-* headers so clients can self-throttle. The exact policy is configured in api/includes/api_config.php.

🏥 Health Calculator API