| Formula | Ideal Weight (kg) |
|---|---|
| Hamwi (1964) | 66.71 |
| Devine (1974) | 65.94 |
| Miller (1983) | 65.97 |
| Robinson (1983) | 65.17 |
| Ideal Weight Range | 53.5 - 72.2 |
The Body Mass Index (BMI) Calculator is a free online tool that allows you to calculate your BMI and understand your weight category based on your height, weight, age, and gender. By entering your measurements, you can quickly see whether you are underweight, normal weight, overweight, or obese, helping you make informed decisions about your health, fitness, and lifestyle.
Use the Metric Unit button to input your height in centimeters and weight in kilograms, or switch to the Imperial Unitbutton to use US customary units such as feet, inches, and pounds. The calculator is designed to be simple, fast, and accurate, providing immediate feedback on your body mass index.
Similarly, use the Gender button to select your gender as male or female. This ensures the results are interpreted correctly according to gender-specific BMI references and helps the calculator provide more accurate guidance on your health and weight status.
In addition to BMI, this tool also calculates the Ponderal Index (PI), which is another measurement of body leanness and corpulence. PI can be particularly useful for very tall or very short individuals. Both BMI and PI results are explained in detail below, including what they mean for your overall health, disease risk, and physical fitness.
Whether you are a teenager, adult, or senior, this calculator provides a reliable starting point to evaluate your body weight in relation to your height, track your weight trends over time, and set realistic goals for a healthy lifestyle.
Body Mass Index (BMI) is a widely used measurement that estimates a person’s body fat based on their height and weight. It is designed to provide a quick and simple way to evaluate whether an individual has a healthy body weight relative to their height. BMI is not a direct measurement of body fat, but it serves as an important screening tool for identifying potential weight-related health risks.
The calculated BMI value is categorized into ranges such as underweight, normal weight, overweight, and obese. These categories help highlight whether someone may be at risk of conditions linked to being underweight, such as malnutrition and weakened immunity, or overweight, such as diabetes, heart disease, and joint problems. In some cases, ranges are further divided into subcategories like severely underweight or very severely obese for more precise classification.
While BMI is not a perfect measure—because it does not distinguish between muscle, bone mass, and body fat—it remains a practical and cost-effective tool for both individuals and healthcare professionals. It gives an initial indication of whether further testing, lifestyle changes, or professional medical advice might be necessary.
The calculator on this page uses standard BMI ranges recommended by health organizations to help you better understand your results. You can refer to the BMI tables below to see detailed categories and how your BMI compares to healthy ranges.
The Body Mass Index (BMI) table for adults provides standardized weight classifications based on BMI values and is widely recognized by the World Health Organization (WHO). This table applies to both men and women aged 20 and older, making it one of the most commonly used reference points for determining healthy weight ranges worldwide.
According to the WHO, BMI values are divided into categories such as severe thinness, normal weight, overweight, and multiple classes of obesity. These classifications help individuals understand whether their current weight may put them at risk for conditions like malnutrition, heart disease, diabetes, or other weight-related health concerns.
You can view the full WHO BMI classification table below to see how different BMI ranges are categorized and compare your own results with these international health standards.
The Body Mass Index (BMI) for children and teens works differently compared to adults. Since kids are still growing, their body composition changes with age and varies between boys and girls. To account for these differences, the Centers for Disease Control and Prevention (CDC)developed age- and sex-specific growth charts that use BMI percentiles instead of fixed ranges. This ensures a more accurate evaluation of whether a child is underweight, at a healthy weight, or at risk of overweight and obesity.
Unlike adults, where BMI categories are the same across all ages and genders,children's BMI values are compared to peers of the same age and sex. This comparison results in a BMI percentile, which indicates how a child’s BMI measures up against others. For example, a child in the 90th percentile weighs more than 90% of children of the same age and sex. The CDC’s official BMI table for ages 2–20 (shown below) outlines the categories based on percentiles.
Understanding BMI percentiles is important because both being underweightor overweight in childhood can increase the risk of long-term health problems such as diabetes, high blood pressure, and heart disease later in life. Tracking BMI early helps parents, caregivers, and healthcare providers take the right steps to support healthy growth and development.
Refer to the table below to see the BMI percentile categories for children and teens recommended by the CDC.
Carrying excess body weight is more than just a cosmetic concern—it can lead to serious health issues and long-term complications. According to the Centers for Disease Control and Prevention (CDC), being overweight significantly increases the risk of chronic diseases, reduced mobility, and decreased quality of life. Maintaining a BMI below 25 kg/m² is generally recommended, but each individual should consult with their doctor to determine a safe and healthy weight range.
As this list shows, being overweight can affect nearly every aspect of health— from cardiovascular wellness to mental well-being. Taking steps to achieve and maintain a healthy BMI through balanced nutrition, regular exercise, and lifestyle adjustments can greatly reduce these risks and improve long-term health outcomes.
Just as carrying excess weight poses health challenges, being underweight also increases the risk of serious medical and lifestyle complications. A low Body Mass Index (BMI) may be a sign of malnutrition, nutrient deficiencies, or an underlying condition that requires medical attention. Maintaining a balanced weight is essential for strong immunity, healthy growth, and long-term well-being.
In some cases, being underweight may be linked to underlying health conditions such as eating disorders (e.g., anorexia nervosa) or chronic illness. If you or someone you know is underweight without a clear cause, it is important to consult a healthcare professional. Proper evaluation and treatment can help restore a healthy balance, reduce risks, and improve overall quality of life.
The Body Mass Index (BMI) is one of the most widely used methods for estimating whether an individual is underweight, at a healthy weight, or overweight. However, BMI has limitations because it does not directly measure body composition. Differences in muscle mass, bone density, fat distribution, sex, and age can make BMI less accurate for certain groups of people. For this reason, BMI should be considered as a screening tool, not a definitive measure of health.
For adults, BMI reflects overall weight rather than body fat percentage. It does not differentiate between fat and lean muscle mass. This means two people with the same BMI may have very different health profiles:
For children and adolescents, BMI is even more complex because growth patterns vary widely. Age, height, and sexual maturation all influence BMI and body fat percentage. While BMI is a better indicator of excess body fat in obese children, it is less accurate for those who are only overweight or underweight. In thin children, BMI differences may reflect fat-free mass (such as muscle, water, or organs) rather than fat levels.
Despite these limitations, BMI is still a useful screening tool for 90–95% of the population. When combined with other assessments such as waist circumference, physical activity levels, and medical history, BMI can provide valuable insights into whether a person is at risk for weight-related health conditions.