Body Mass Index — metric or imperial, with the healthy weight range for your height.
Body Mass Index is the simplest screening metric for assessing whether someone’s weight is in a healthy range for their height. It’s computed as weight ÷ height²in kilograms and meters. The calculator below supports both metric and imperial inputs, classifies the result against World Health Organization categories, and shows the weight range that would place you in the ‘healthy’ band.
For your height, the WHO healthy weight range is 56.7–76.3 kg.
BMI is a population-screening metric, not a personal diagnosis. It doesn’t account for muscle mass, frame size, age, or ethnicity. Treat the result as one input among many.
Metric (kg, cm) is the default. Switch to imperial if you measure weight in pounds and height in feet-and-inches.
Your BMI updates as you type. The category badge changes colour based on the WHO range your number falls into.
Below the BMI number, the calculator shows the weight range — in your chosen unit — that would put you between 18.5 and 24.9, the WHO 'healthy' band.
| BMI range | Classification |
|---|---|
| < 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25.0 – 29.9 | Overweight |
| 30.0 – 34.9 | Obese class I |
| 35.0 – 39.9 | Obese class II |
| ≥ 40.0 | Obese class III |
Devised by Belgian statistician Adolphe Quetelet in the 1830s as a population-level descriptor and popularised by physiologist Ancel Keys in 1972 (who coined the modern name). It's an imperfect tool — Quetelet himself was clear that his index described a population, not individuals — but its simplicity has kept it in clinical use for nearly two centuries.
Modern clinicians increasingly pair BMI with waist circumference, waist-to-height ratio, and body-fat percentage. Convertitive is a measurement converter, not a diagnostic tool — for personal health decisions consult a clinician with access to your full medical history.