BMI Calculator
Estimate your Body Mass Index from height and weight, with the WHO adult category and a healthy-weight range for your height.
BMI is a quick screening tool, not a diagnosis. It is interpreted alongside age, muscle mass, and body-composition context.
Your measurements
centimeters (cm)
kg
Guidelines
- Underweight < 18.5 — may signal low energy intake or underlying illness; worth a check-up.
- Normal weight 18.5–24.9 — associated with the lowest all-cause mortality in most populations.
- Overweight 25–29.9 — elevated risk, especially if abdominal fat is high.
- Obesity ≥ 30 — graded I (30–34.9), II (35–39.9), and III (≥ 40, severe). Higher grades carry greater cardiometabolic risk.
These are the World Health Organization (WHO) thresholds for adults. They are not applicable to children/adolescents (who use age-and-sex percentile charts), athletes with high lean mass, or pregnancy.
Worked reference: a 175 cm, 75 kg adult has a BMI of 75 ÷ (1.75 × 1.75) ≈ 24.5, putting them at the top of the normal range. The corresponding healthy weight band is roughly 56.7–76.6 kg.
Data sources
World Health Organization — Obesity and overweight fact sheet · Centers for Disease Control and Prevention (CDC) — About Adult BMI · Calculator.net — BMI Calculator · National Institutes of Health (NHLBI) — Calculate your BMI.
This is an estimate for screening only and is not a medical diagnosis. BMI does not measure body fat directly and can misclassify very muscular or older adults. All math runs in your browser.