Enter your weight and height. The tool calculates BMI using the standard formula: weight (kg) ÷ height² (m²). The category shown is indicative only.
About this BMI calculator (Body Mass Index)
This free BMI calculator helps you estimate your Body Mass Index (BMI) from two simple measurements: your weight and your height. BMI is a widely used indicator that provides a quick, standardized way to compare body weight relative to height. Because it is simple, it is often used in everyday contexts (fitness, tracking changes over time) and in large-scale health studies. The BMI formula is: BMI = weight (kg) ÷ height² (m²). For example, a person who weighs 70 kg and is 1.75 m tall has a BMI of 70 ÷ (1.75 × 1.75) ≈ 22.9.
Many people use BMI as an initial reference to see an indicative category such as underweight, normal weight, overweight, or obesity. These cutoffs can be helpful for a high-level overview, but BMI has important limitations. It does not directly measure body fat, body composition, muscle mass, bone density, or fat distribution. As a result, a very muscular person may have a high BMI without having excess body fat, and BMI may not reflect health risks equally for all ages and populations. In other words, BMI is a useful screening indicator, but it is not a diagnosis.
This calculator intentionally focuses on speed and privacy. The computation runs locally in your browser: no account is required, and your inputs are not stored or transmitted by this page. You can use it on desktop or mobile for quick checks, to follow a trend over time, or to validate a BMI value from another source.
If you have health concerns, recent weight changes, or you need personalized guidance (for example, during pregnancy, for children/teens, or for medical conditions), it’s best to consult a qualified healthcare professional. BMI can be one piece of information among others (waist circumference, clinical history, lifestyle, lab results) to get a more accurate picture.
Note: the displayed category is indicative only and should not be used as a medical diagnosis.
What is this BMI calculator used for?
This BMI calculator is used to estimate your Body Mass Index (BMI) from your height and weight. BMI is a simple numerical indicator that relates body weight to height and is commonly used as a first screening tool to classify weight status.
Who is this tool useful for?
- Individuals who want a quick BMI estimate
- People tracking changes in weight over time
- Fitness beginners looking for a general reference point
- Students learning how BMI is calculated
Concrete examples
- Checking your BMI after entering a new weight measurement
- Comparing BMI values at different moments in time
- Verifying a BMI value calculated manually or elsewhere
Common mistakes to avoid
- ❌ Forgetting to convert height from centimeters to meters
- ❌ Assuming BMI directly measures body fat
- ❌ Using BMI alone to draw medical conclusions
This calculator applies the standard formula automatically, but the interpretation of the result should remain cautious.
Limits and possible alternatives
BMI does not take into account muscle mass, body composition, age, sex, or fat distribution. As a result, it may not accurately reflect health risks for all individuals.
- Body fat percentage measurements
- Waist circumference and clinical assessments
Educational summary
In summary, this BMI calculator provides a fast way to estimate Body Mass Index using weight and height. It is useful as a general reference indicator, but it should not replace professional medical advice or a full health evaluation.