Body Mass Index (BMI) is a number calculated from your height and weight (weight in kg divided by height in m squared). It is a widely used screening tool: under 18.5 = underweight, 18.5-24.9 = normal, 25-29.9 = overweight, 30+ = obese.

Is BMI an accurate measure of health?

BMI is a population-level screening tool, not a diagnostic measure. It does not account for muscle mass, bone density, fat distribution, age, or ethnicity. A muscular athlete may have an overweight BMI despite being very healthy.

What is a healthy BMI?

The World Health Organization defines 18.5-24.9 as the healthy BMI range for adults. However, optimal BMI varies by age and ethnicity. Some guidelines suggest a lower threshold for Asian populations.

How is BMI different from body fat percentage?

BMI estimates weight relative to height but does not measure body fat directly. Body fat percentage tells you what fraction of your weight is fat tissue. Two people with the same BMI can have very different body compositions.

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BMI Calculator

Calculate your Body Mass Index (BMI) with a visual scale and healthy weight range. Supports metric and imperial. Free BMI calculator — no sign-up.

Weight: 70 kg

Height: 170 cm

About This Tool

Calculate your Body Mass Index (BMI) instantly in metric or imperial units. See where you fall on the BMI scale, your weight category, and the healthy weight range for your height.