Updated: July 2026
What is the BMI Calculator?
The BMI Calculator (Body Mass Index) is one of the most famous metrics in the world, created to quickly assess whether your current weight is appropriate for your height and discover your ideal weight. It is the nutritional screening standard used by the World Health Organization (WHO), and the calculation is the same for adult men and women.
To calculate it, the math is simple: just divide your weight (in kilograms) by your height squared (in meters). Our online calculator saves you that bill, delivering the result and the exact WHO classification right away.
How to use the BMI Calculator
Using the tool is very simple:
- Enter your current weight in kilos.
- Enter your height in centimeters.
- Instantly see your BMI, the WHO classification in a visual bar and the weight range considered ideal for your height.
There is no need to click any button: the result is automatically recalculated with each number entered.
Difference: The Ideal Weight Dashboard
The vast majority of BMI calculators on the internet only report a number. The problem is that people don't just want a number, they want to know: "How many kilos do I need to lose or gain?".
To solve this, our tool has an integrated algorithm that does the reverse calculation! From the moment you enter your height, we display what the Minimum and Maximum Ideal Weight is for your body.
And there's more: the system will inform you clearly and objectively your personal goal. If you are overweight, we will let you know exactly how many kilos you need to dry. If you are underweight, we will inform you how many kilos of mass you will need to gain to reach the "green range" of health.
BMI Classification Table (WHO)
| BMI | Classification |
|---|---|
| Under 18.5 | Underweight (may indicate malnutrition) |
| 18.5 to 24.9 | Normal weight (the dreamed "green belt") |
| 25.0 to 29.9 | Overweight (warning sign) |
| 30.0 to 34.9 | Grade I obesity |
| 35.0 to 39.9 | Obesity grade II (severe) |
| 40.0 or more | Obesity grade III (morbid) |
BMI Limitations (E-E-A-T Alert)
BMI is incredible for public health, but it has a serious flaw in individual assessments: it doesn't know how to differentiate between fat and muscle mass. Muscle is a denser and heavier tissue than fat. Because of this, strength athletes, crossfit practitioners and bodybuilders often receive the diagnosis of "Overweight" or even "Obesity" in BMI calculators, even though they are extremely healthy. Pregnant women and the elderly (who lose bone mass) should also not use BMI as a definitive metric. Always look for a bioimpedance test with a nutritionist!