Estimate adult body mass index (BMI) in metric or imperial units. See the WHO category on a visual scale, a healthy weight range for your height, and a clear non-medical disclaimer. Age and sex are optional context only.
BMI = weight (kg) ÷ [height (m)]². Imperial inputs are converted to metric before the formula.
WHO adult categories used here: underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), obesity (≥30).
Healthy weight range is the weight band that keeps BMI between 18.5 and 24.9 for your height.
BMI = kg ÷ m²; healthy kg ≈ 18.5·m² … 24.9·m²
Height 170 cm, weight 68 kg → height 1.70 m.
1.70² = 2.89; 68 ÷ 2.89 ≈ 23.5 → normal (18.5–24.9).
At the same height, 86 kg → ≈ 29.8 → overweight.
Body mass index relates weight to height as a quick screening ratio. It does not measure body fat directly.
Not always. Muscle mass, age, and ethnicity can change how BMI maps to health. Use it as a starting point, not a diagnosis.
No. Children and teens need age- and sex-specific percentiles. This tool focuses on standard adult WHO cutoffs.
Not in this calculator. Sex is optional context; the WHO adult formula is the same for all adults here.
No. Talk with a qualified clinician before making health decisions.
No. Everything runs in your browser for this tool.
BMI is a screening estimate only and is not medical advice. It does not diagnose disease or replace care from a qualified health professional.
WHO adult categories apply best from about age 20 upward.
Stored only in your browser for this session. Not used in the WHO adult formula.
Your BMI
Category: Normal
WHO adult BMI scale
| Category | Normal |
|---|---|
| Healthy weight (kg) | 53.5–72 kg |
| Healthy weight (lb) | 117.9–158.7 lb |
BMI is a screening estimate only and is not medical advice. It does not diagnose disease or replace care from a qualified health professional.