Reference Desk — Diagnostic

What the number means,and what it doesn't.

BMI is a 19th-century actuarial shortcut, not a clinical truth. Used carefully — alongside waist-to-height ratio and context — it remains the standard population screen. Compute yours below.

Inputs
cm
kg
cm
yr
Body Mass Index
26.0
Overweight
Waist-to-height
0.50
Increased
Spectrum — CDC Classification
Under
0
Healthy
18.5
Over
25
Class I
30
Class II
35
Class III
40
26.0
Risk Reading

Elevated. Cardiometabolic risk begins to climb.

BMI does not distinguish lean mass from adipose tissue. Athletes routinely register "overweight" by BMI alone. Combine with waist-to-height ratio (target < 0.5), metabolic panel, and a clinician's reading.

Method — Notes

Formula.BMI = kg / m². Identical to Quetelet's 1832 index.

Limitations. Insensitive to body composition, age, ethnicity, frame.

Better used with. Waist circumference, A1C, lipid panel, blood pressure.