Free tool

BMI Calculator

Calculate your Body Mass Index using metric or imperial units. Your result is shown as a screening estimate with context — not a health verdict or diagnosis.

BMI
24.2
Standard reference range category
Healthy weight

Based on standard reference bands, a BMI of 24.2 falls in the Healthy weight range. BMI is a screening estimate, not a diagnosis or a measure of health.

This calculator provides estimates for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Individual needs vary. Consult a qualified healthcare provider or registered dietitian before making significant changes to your diet or health routine.

How to use this calculator

Choose metric (kilograms and centimetres) or imperial (pounds and inches), then enter your weight and height. The calculator shows your BMI value and the standard reference band it falls in, described neutrally as context.

Understanding your BMI

BMI is calculated by dividing weight in kilograms by the square of height in metres. It is a useful population-level screening tool, but it has well-documented limitations at the individual level: it does not distinguish muscle from fat, it does not account for fat distribution, and its thresholds were developed on limited population samples. Use your result as one data point, not a measure of your worth or overall health.

Disclaimer

This calculator provides estimates for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Individual needs vary. Consult a qualified healthcare provider or registered dietitian before making significant changes to your diet or health routine.

Track this in OptiAI

OptiAI lets you log health metrics including weight, alongside your nutrition, fitness, and goals — so you can track meaningful trends over time rather than relying on a single number snapshot.

Frequently asked questions

What is a healthy BMI?

Standard reference bands (WHO): under 18.5 is underweight, 18.5–24.9 is healthy weight, 25–29.9 is overweight, and 30 or above is obese. These are population screening categories, not individual health verdicts.

Is BMI an accurate measure of health?

BMI is a simple screening tool used at the population level. It does not account for muscle mass, bone density, fat distribution, age, sex differences, or ethnicity. Many people with a BMI in the overweight or obese range are metabolically healthy, and some in the normal range are not. See our guide on BMI limitations for a fuller picture.

Should I use metric or imperial?

Either gives the same result. Metric uses kilograms and centimetres; imperial uses pounds and inches. The calculator converts automatically.

Is this medical advice?

No. This calculator provides estimates for informational purposes only. Always consult a qualified healthcare professional before making decisions about your health.

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