⚖️ BMI Calculator

What This Calculator Does

This calculator works out your Body Mass Index (BMI) from your height and weight, in either metric or imperial units, and tells you which standard category the result falls into. BMI is a widely used screening number that gives a quick, rough sense of whether your weight is in a healthy range for your height. Enter your measurements and it does the calculation and interprets the result instantly.

BMI is popular because it is simple and gives a fast, standardized snapshot. It is important to understand from the outset, though, that it is a general screening tool, not a measure of health or body composition for any individual — a point worth keeping in mind as you read your result. This calculator gives you the number and its category; the context below explains what that does and does not mean.

How BMI Is Calculated and Categorized

BMI is calculated from your weight relative to your height — specifically, weight divided by height squared. The resulting number is then placed into standard categories: roughly, under 18.5 is considered underweight, 18.5 to 24.9 is the normal or healthy range, 25 to 29.9 is overweight, and 30 and above is in the obese range. These thresholds are the widely used standard, which is why BMI gives a consistent, comparable figure across people.

The calculation works the same regardless of units — you can enter height and weight in metric (centimeters and kilograms) or imperial (feet, inches, and pounds), and the calculator handles the conversion. The single resulting number is what makes BMI convenient: it reduces the relationship between height and weight to one figure that fits into clear categories. That simplicity is its strength as a quick screening tool, and also, as the next section explains, the source of its well-known limitations.

Quick Tips

• BMI is a quick screening number, not a measure of your individual health or body composition.
• It does not distinguish muscle from fat, so muscular people may read as overweight despite being lean.
• Use it as a rough starting point or to track a general trend, not as a diagnosis.
• For a real assessment, a healthcare professional considers BMI alongside many other factors.

Frequently Asked Questions

How is BMI calculated?

It is your weight divided by your height squared. The calculator accepts metric or imperial units and produces a single number, then places it in the standard categories: underweight, normal, overweight, or obese.

What is a healthy BMI range?

The widely used standard considers 18.5 to 24.9 the normal or healthy range, with under 18.5 underweight, 25 to 29.9 overweight, and 30 and above obese. These are general thresholds, not individual judgments.

Is BMI an accurate measure of health?

Not on its own. BMI is a rough screening tool that does not distinguish muscle from fat or account for age, sex, or where fat is carried. It is a starting point, not a diagnosis or a measure of individual health.

Should I be concerned about my BMI?

BMI can flag a possible concern worth discussing, but it is not a verdict. A healthcare professional can assess your health properly, considering BMI alongside the many other factors it does not capture. This tool is informational, not medical advice.