BMI Calculator

Enter your height and weight; instantly see your Body Mass Index, category, and the weight range considered normal for your height.

Runs 100% in your browser — your information is never sent to a server.
Your BMI Value
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Normal weight range for this height
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BMI Scale
Underweight Normal Overweight Obese

How to Interpret BMI — and Its Limitations

Body Mass Index (BMI) is an easy-to-calculate screening measure the World Health Organization (WHO) has used since the 1990s to classify the weight-to-height relationship at a population level. This tool takes the height and weight you enter, runs them through BMI = weight (kg) / height (m)², places the result into one of four common categories (underweight, normal, overweight, obese), and also calculates the weight range that corresponds to the "normal" bracket (18.5–24.9) for your height.

BMI is widely used in family medicine and public health screening as a quick first-pass indicator: it's less useful for diagnosing an individual and more practical for tracking a population, or your own trend over time — for example, whether your category has shifted since your last annual check-up. Looking at the trend over time, rather than a single measurement, makes BMI more meaningful; measuring it every few months and seeing your category move toward or away from a threshold tells you more than a single day's reading.

BMI has well-known limitations: it doesn't distinguish between muscle and fat tissue (which is why someone who exercises regularly and has high muscle mass can come out as "overweight" by BMI alone), it says nothing about where fat is distributed in the body (waist circumference or visceral fat, which can be more predictive of cardiovascular risk), and the same BMI value can carry a different health risk across ethnic groups (for example, in some Asian populations) — which is why some countries use different threshold values for their own populations. Because muscle mass naturally declines with age, the same BMI value can correspond to a different body composition in an older adult than in a younger one. For a more complete picture, complementary measures such as waist circumference or body fat percentage can also be useful.

The height and weight you enter are processed entirely in your browser; this tool never sends data to a server, doesn't require an account, and doesn't store the values you enter anywhere — the information disappears the moment you close the page.

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Frequently Asked Questions

Body Mass Index (BMI) is calculated by dividing your weight by the square of your height: BMI = Weight (kg) / Height (m)². It is a widely used screening measure from the World Health Organization (WHO) and reflects the weight-to-height ratio, not body fat percentage directly.

Commonly accepted thresholds are: below 18.5 Underweight, 18.5–24.9 Normal, 25–29.9 Overweight, and 30 or above Obese.

No. BMI does not account for muscle mass, fat distribution, age, sex or bone structure. For example, athletes with high muscle mass may show an artificially high BMI. Because of this, BMI is a general screening indicator on its own, not a diagnostic tool.

This tool is for informational purposes only and is not a substitute for medical advice. If you have any concerns about your weight or health, we recommend consulting a physician or dietitian for a personalized assessment.

No. BMI only measures the height-to-weight ratio; waist circumference reflects visceral fat, and body fat percentage reflects the proportion of total fat mass in the body. These three measures complement each other, they don't replace one another — the site also has a separate Body Fat Percentage calculator.

No. This tool doesn't require an account or a server connection; the values you enter are only processed in your browser's memory and disappear when you leave the page. This kind of special-category health data never reaches us in any way.

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