BMI Explained: What Your Number Really Means
2026-05-23
Quick Answer
Quick Answer: BMI (Body Mass Index) is weight (kg) ÷ height (m)². A result of 18.5–24.9 is considered normal weight for adults (WHO). Calculate yours with our BMI Calculator.
What is BMI?
BMI is a simple screening number based on height and weight. It helps categorize whether an adult may be underweight, normal weight, overweight, or obese.
BMI categories (WHO)
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Normal |
| 25 – 29.9 | Overweight |
| 30+ | Obese |
Limitations
BMI does not measure body fat directly. Athletes with high muscle mass may have a high BMI without excess fat. It is a screening tool, not a diagnosis.
Healthy weight range
For a given height, the healthy BMI band (18.5–24.9) maps to a weight range. Our calculator shows this when you enter metric height.
Try It Yourself
Check your BMI in seconds with the BMI Calculator. Also see our Ideal Weight Calculator.
Frequently Asked Questions
Is BMI accurate for everyone?
It is useful for most adults but less accurate for very muscular individuals, elderly adults, and some ethnic groups. Discuss results with a healthcare provider.
What is a good BMI?
For most adults, 18.5–24.9 is the normal range according to the WHO.
Disclaimer: This article is for informational purposes only and is not medical advice.