BMI Calculator

BMI (body mass index) is weight divided by height squared. It's used everywhere because it's fast and free — not because it's precise. It can't tell muscle from fat, doesn't know where your fat sits (visceral fat around organs matters far more than fat under the skin), and misreads athletes, older adults, and several ethnic groups.

Use it as a rough screening signal, nothing more. If your number surprises you, waist circumference and body composition are better next questions — and our consult can help you figure out what's worth discussing with a doctor.