BMI Calculator
Range: 50 - 500
Range: 1 - 8
Range: 0 - 11
Your BMI
22.1
Normal weight
Healthy Weight Range
125 - 169
lbs
BMI Scale
BMI Categories
| Category | BMI Range |
|---|---|
| Underweight | < 18.5 |
| Normal weight | 18.5 - 24.9 |
| Overweight | 25 - 29.9 |
| Obese (Class 1) | 30 - 34.9 |
| Obese (Class 2) | 35 - 39.9 |
| Obese (Class 3) | 40+ |
About BMI
BMI is a screening tool that uses height and weight to estimate body fat and health risks. However, it doesn't account for muscle mass, bone density, age, or distribution of fat. Athletes may have a high BMI due to muscle mass. Consult a healthcare provider for a comprehensive health assessment.
About the BMI Calculator
The BMI Calculator computes your Body Mass Index, a quick screening number that relates your weight to your height. It uses the standard formula of weight in kilograms divided by height in meters squared (kg/m2), or the imperial equivalent of weight in pounds times 703 divided by height in inches squared, and then places the result into a category.
The tool reports your BMI value and the standard adult classification: underweight below 18.5, normal weight from 18.5 to 24.9, overweight from 25 to 29.9, and obese at 30 and above. These thresholds come from World Health Organization guidance and are widely used in clinics and population health studies as a fast, inexpensive screen.
Common use cases include tracking weight-management progress, setting a target weight range for your height, and getting a baseline before pairing it with metabolic tools like the BMR Calculator to plan calorie intake. It is also frequently used as a first-pass health indicator in fitness apps and routine checkups.
An important tip is that BMI is a screening tool, not a diagnosis. It does not distinguish muscle from fat, so very muscular athletes can register as overweight while it may understate body fat in older adults. Treat it as one signal alongside waist circumference, body composition, and a clinician's assessment.
Frequently asked questions
- What is the formula for BMI?
- BMI equals weight in kilograms divided by height in meters squared. In imperial units it is weight in pounds multiplied by 703, then divided by height in inches squared.
- What BMI range is considered healthy?
- For most adults a BMI of 18.5 to 24.9 is classified as normal weight. Below 18.5 is underweight, 25 to 29.9 is overweight, and 30 or above falls into the obese range.
- Is BMI accurate for athletes?
- Not always. Because BMI cannot separate muscle from fat, muscular athletes can score in the overweight range despite low body fat. Waist measurement or body-composition testing gives a fuller picture in those cases.
- Does BMI work the same for children?
- No. For children and teens, BMI is interpreted using age- and sex-specific percentile charts rather than the fixed adult cutoffs, so a pediatric BMI-for-age tool should be used instead.