Enter weight and height to calculate Body Mass Index, view your adult BMI category, and understand the result's limits.
BMI = weight / (height²)Body Mass Index is a screening metric based on weight and height. For adults, BMI is commonly grouped into underweight, healthy weight, overweight, and obesity categories, but it is not a diagnosis by itself.
| Symbol | Variable | Description |
|---|---|---|
| BMI | Body Mass Index | Calculated index in kg/m². |
| weight | Body weight | Body mass in kilograms (kg). |
| height | Body height | Body height in meters (m). |
Enter weight
Input your body weight in kilograms.
Enter height
Input your body height in meters (for example, 1.75).
Click Calculate
The calculator returns your BMI value and adult BMI category instantly.
Adult BMI categories are commonly used as a screening tool for weight status. A BMI below 18.5 is usually classified as underweight, 18.5 to 24.9 as healthy weight, 25.0 to 29.9 as overweight, and 30.0 or above as obesity.
| Category | Adult BMI range |
|---|---|
| Underweight | Below 18.5 |
| Healthy weight | 18.5 to 24.9 |
| Overweight | 25.0 to 29.9 |
| Obesity | 30.0 or higher |
BMI is popular because it is fast and easy to calculate, but it does not directly measure body fat, muscle mass, bone density, waist size, or health risk. Athletes, older adults, pregnant people, and children may need different interpretation.
Use the BMI calculator as a first screening step. If the result is outside the healthy-weight range, combine it with waist circumference, lifestyle factors, blood pressure, labs, medical history, and clinician advice before making health decisions.
This BMI calculator uses metric inputs: kilograms for weight and meters for height. If your height is in centimeters, divide by 100 before entering it. For example, 175 cm should be entered as 1.75 m.