BMI & Body Composition Calculator
Calculate Body Mass Index (BMI), WHO weight categories, healthy weight targets, and daily maintenance calories (TDEE).
How to Use BMI & Body Composition Calculator
1. Select Metric or Imperial Units
Toggle between centimeters/kilograms or feet/inches/pounds and enter your height and current body weight.
2. Instant WHO Classification
Your Body Mass Index is calculated instantly against World Health Organization criteria (Underweight, Normal, Overweight, Obese).
3. View Healthy Weight Bounds
Review the visual gauge and see the exact target weight range corresponding to a healthy BMI (18.5–24.9) for your height.
How This Utility Works
Accurate dual-unit (Metric & Imperial) Body Mass Index (BMI) calculator. Evaluates body mass against official World Health Organization (WHO) categories, plots your score on an interactive color-coded spectrum meter, determines healthy weight boundaries, and estimates Basal Metabolic Rate (BMR via Mifflin-St Jeor) and TDEE calorie burn.
Your body metrics, age, weight, and fitness statistics remain exclusively on your device. No health data is stored in remote databases.
Frequently Asked Questions
What is a healthy BMI range?
According to the World Health Organization (WHO), a BMI between 18.5 and 24.9 represents normal, healthy weight for adults.
Does BMI distinguish between muscle and fat mass?
BMI is an epidemiological screening indicator based on height and weight. For muscular athletes, BMI may overestimate body fat, which is why BMR and TDEE metrics are also provided.
What formula is used for BMR and Calorie calculations?
This calculator implements the Mifflin-St Jeor formula, widely recognized by clinical nutritionists as the most reliable standard for estimating resting metabolic rate.
World Health Organization (WHO) BMI Classifications
| Classification | BMI Range (kg/m²) | Cardiometabolic Risk | Recommended Action |
|---|---|---|---|
| Underweight | < 18.5 | Nutritional deficiency risk | Nutrient-dense caloric surplus |
| Normal Weight | 18.5 – 24.9 | Lowest health risk baseline | Maintain balanced activity & diet |
| Overweight (Pre-obese) | 25.0 – 29.9 | Moderate elevated risk | Moderate calorie control & regular cardio |
| Obesity Class I | 30.0 – 34.9 | High risk (Type 2 Diabetes, BP) | Structured caloric deficit & resistance training |
| Obesity Class II & III | ≥ 35.0 | Very high clinical risk | Consult primary care physician / clinical nutritionist |