Tools / Calculator 01
BMI Calculator.
Body Mass Index from your height and weight. A starting line for population-level screening, not a finish line for your protocol.
Your BMI
—
| Underweight | < 18.5 |
| Normal | 18.5 – 24.9 |
| Overweight | 25 – 29.9 |
| Obese | 30+ |
How it's calculated.
The BMI formula is the same everywhere; only the units change.
- Metric. BMI = weight (kg) ÷ height (m)².
- Imperial. BMI = (weight (lb) × 703) ÷ height (in)².
Source: World Health Organization, Obesity: preventing and managing the global epidemic, WHO Technical Report Series 894, 2000.
What BMI does not measure.
- Body composition. A 5'10", 200 lb athlete with 12% body fat has the same BMI (28.7, "overweight") as someone with 35% body fat. The number says nothing about muscle versus fat.
- Fat distribution. Visceral fat carries different cardiometabolic risk than subcutaneous fat. BMI ignores both.
- Sex, age, ethnicity. The WHO categories were derived from population data that skews toward European adults. Asian-American and Pacific guidelines often use lower thresholds (overweight ≥ 23, obese ≥ 27.5).
- Trend. A single BMI reading is a snapshot. The trajectory over weeks tells you more than the number on any one day.