What BMI can and can't tell you

BMI — Body Mass Index — is weight (kg) divided by height (m) squared. It sorts people into categories: under 18.5 underweight, 18.5–24.9 normal, 25–29.9 overweight, 30+ obese.

What it’s good for

BMI is a fast, cheap population-level screen. Across large groups it tracks with health risk reasonably well, which is why clinicians and researchers use it.

What it can’t do

BMI doesn’t know the difference between muscle and fat. A muscular person can read “overweight” while being lean and healthy. It says nothing about where you carry fat, your fitness, your blood markers, or how you feel. It’s one signal, not a verdict.

How to use it

Treat BMI as a starting reference, not a goal. Trends over time, waist measurements, progress photos, strength and energy tell you far more. Our BMI calculator shows your number and category — with this honest context attached.

If your aim is to change your body composition, a structured plan beats chasing a single number. Build one here — training and nutrition together.

General education, not medical advice. If you have concerns about your weight or health, talk to a healthcare professional.