BMI Calculator
Enter your weight and height to get your BMI, its category, and the healthy weight range for your height. BMI is a quick screening measure used by doctors worldwide — it updates live as you type.
What this means
BMI compares your weight to your height: weight in kilograms divided by height in meters squared. Values under 18.5 are underweight, 18.5–24.9 are healthy, 25–29.9 overweight, and 30+ indicate obesity.
How we calculate it
Formula
BMI = weight (kg) ÷ height (m)².Worked example
Weight 70 kg, height 175 cm:
- 1175 cm = 1.75 m
- 21.75² = 3.0625
- 370 ÷ 3.0625 ≈ 22.9 (healthy)
Important assumptions
- BMI does not distinguish muscle from fat; athletes may show a high BMI with low body fat.
Frequently asked questions
What is a healthy BMI?
The World Health Organization defines 18.5–24.9 as normal. Below 18.5 is underweight and 25+ is overweight.
Is BMI accurate for athletes?
Not always — it cannot tell muscle from fat. Muscular people may fall in the overweight range despite being lean.
Guide
BMI Calculator Guide: How to Read Your Body Mass Index
BMI is a quick screening number, not a diagnosis. Here is how to use it correctly and what to look at next.
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