Body Mass Index (BMI) is one of the most widely used methods to assess whether a person’s body weight is appropriate for their height. It provides a simple numeric value that helps identify if you are underweight, at a normal weight, overweight, or obese. Healthcare professionals often use BMI as a quick screening tool, though it is not the only measure of health.
By understanding your BMI, you can gain valuable insight into your overall health and take steps to maintain or improve your weight. On this page, you can use our free BMI calculator to get your result instantly.
The BMI formula is simple and requires only your weight and height:
BMI = frac{ ext{Weight (kg)}}{ ext{Height (m)}^2}
BMI = frac{ ext{Weight (lbs)} imes 703}{ ext{Height (in)}^2}
For example: If you weigh 70 kg and your height is 1.75 m, your BMI would be:
BMI = frac{70}{1.75^2} = 22.9
This value falls within the normal weight range.
The World Health Organization (WHO) defines BMI categories as follows:
These categories provide general guidelines, but keep in mind that individual health can vary based on lifestyle, genetics, and other factors.
Maintaining a healthy BMI is linked to a lower risk of many chronic health conditions. Being overweight or obese may increase the likelihood of:
On the other hand, being underweight can also cause problems such as:
Knowing your BMI can help you understand whether you may need to make changes to your diet, exercise routine, or lifestyle to improve your health.
Although BMI is a useful and quick indicator, it has several limitations:
For example, a muscular athlete might have a high BMI but a low body fat percentage. Similarly, someone with normal weight could still carry excess abdominal fat, which increases health risks.
For this reason, BMI should not be used as the only measure of health. Other important tools include waist circumference, body fat analysis, blood tests, and medical check-ups.
If your BMI is outside the normal range, you can take practical steps to achieve a healthier weight:
Use the BMI calculator on this page to instantly check your body mass index. Simply enter your weight and height, and the calculator will display your BMI result along with the category it falls into. This tool is completely free, quick, and works with both metric and imperial units.
A healthy BMI for adults is between 18.5 and 24.9. This range is associated with the lowest risk of weight-related health problems.
Not always. BMI may not be accurate for athletes, bodybuilders, older adults, or people with high muscle mass, as it does not differentiate between fat and muscle.
Yes, but BMI for children and teens is interpreted differently. Pediatric BMI percentiles are used instead of fixed ranges, since body composition changes with age and growth.
To reduce BMI, combine a balanced diet with regular physical activity. Avoid extreme diets and focus on long-term lifestyle changes. Consulting a healthcare professional is recommended.
Research suggests that BMI may not reflect health risks equally across different ethnic groups. For example, some populations may develop health risks at lower BMI levels.
If your BMI is under 18.5, you may need to increase your calorie intake with nutrient-rich foods and consult a doctor to rule out underlying health issues.