How to read your result
- Under 18.5 — Underweight
- 18.5 – 24.9 — Normal weight
- 25.0 – 29.9 — Overweight
- 30.0 and above — Obese
These are the WHO cutoffs and apply to most adults aged 20 and over. They’re a screening tool, not a diagnosis.
When BMI is misleading
BMI was designed for population-level statistics, not for telling you about your body. It can mislead in predictable ways:
- Muscular people. Lifters and athletes often score in the “overweight” or even “obese” range despite low body fat, because muscle is denser than fat.
- Older adults. People lose muscle and gain fat as they age, so a “normal” BMI can hide unhealthy body composition.
- Different ethnicities. Risk thresholds differ across populations — for example, several Asian populations face elevated metabolic risk at lower BMIs than the WHO defaults assume.
- Pregnancy. BMI isn’t meaningful during pregnancy.
- Children & teens. Different charts (BMI-for-age percentiles) apply.
If you want a better picture of body composition, more useful measures include waist circumference, waist-to-height ratio, and (more involved) DEXA scans or trained skinfold measurements.
What to do with the number
Use it as a single data point alongside how you actually feel — energy, sleep, strength, recovery — and observable trends in your body over months, not days. If you’re concerned by the result, talk to a doctor or a registered dietitian rather than a YouTube fitness influencer.