BMI calculator

Calculate your body mass index:

Your BMI is

What is Body Mass Index?

Body Mass Index (BMI) shows the ratio between a person’s body weight and height. This index is widely used as a general indicator of whether a person has a healthy body weight per height or not.

The World Health Organization (WHO) classifies results into 4 major weight categories: underweight, normal weight, pre-obesity, and obesity. In addition, peripheral areas of the BMI spectrum are further classified: Obesity class I, II, and III, or more commonly known as obese, severely obese, and morbidly obese.


Table 1. Body mass index table.

BMI formula

You can easily calculate the body mass index using the BMI calculator at the top of the page, or calculate it yourself, by dividing your body mass by the square of your height:

BMI formulas (Metric Units & US Units)

Formula 1. BMI formulas (Metric Units & US Units)

EXAMPLE: A person is 175 cm tall and weighs 100 kg. In this case, the formula looks like this: BMI = 100 kg / 1.75 m² = 100 / 3.0625 = 32.65 kg / m²

With that result, the person falls into the “Obesity class I” category.

“Blind spots” of BMI

Although BMI is one of the most common indicators of healthy weight, it still has its weaknesses. The main concern with BMI is that only weight and height are taken into account in the calculation, although they are only “the tips of the iceberg”.

As people have different body types and the distribution of muscle, bone mass, and fat varies from person to person, in addition to BMI, other body tests, measurements, etc., such as body composition analysis, should be used to assess people’s physical condition.

For instance, the BMI of a 183 cm and 113 kg sumo wrestler and a bodybuilder can be precisely the same, which gives the impression of a bodybuilder being strongly overweight, although the athlete’s high weight is due to great muscle mass.

Same BMIs, different body types

Figure 1. Same BMIs, different body types.

Being underweight or overweight can be very dangerous to health, so although body mass index isn’t an ideal indicator of healthy body weight, it is still a good indicator of whether further analysis or consultation should be considered.

There are slightly different nuances in the calculation of children’s body mass index compared to adults, because especially for children, their age, gender, etc. must be taken into account. You can read more about children’s BMI figures and charts on the World Health Organisation’s website.

How BMI still does its job?

Even though BMI can be misleading in terms of body types, it still gives you a good overview if there is room for improvement for your body or is everything already the way it should.

Here’s a perfect example of why body weight isn’t the best indicator of how healthy a person really is, but BMI, on the other hand, gives a clear grasp:

Different BMIs, same body weight

Figure 2. Different BMIs, same body weight.

Especially in cases like shown in the picture, BMI is the right tool to assess your body condition.

Risks associated with obesity

As you know, being overweight can lead to several severe health problems and diseases, including:

  • Type 2 diabetes,
  • High blood pressure,
  • Sleep apnea,
  • Kidney disease,
  • Heart disease and strokes,
  • Certain types of cancer,
  • Osteoarthritis,
  • Fatty liver disease,
  • Pregnancy problems, such as high blood sugar during pregnancy, high blood pressure, and an increased risk for cesarean delivery (C-section).

All of the above, as well as many other health problems, can strike a person in the case of obesity, and even become life-threatening. Therefore, it’s important to keep your BMI below 25 kg/m² but to determine which BMI result is the healthiest for your body type, consult with specialists.

Risks associated with being underweight

However, obesity is not the only cause of serious health problems. The same risks are with being underweight. Although underweight people are less likely to suffer from severe health problems, due to lack of essential nutrients and underweight, they still may experience:

  • Osteoporosis (bones are fragile and more prone to breaking),
  • Skin, hair or teeth problems,
  • Frequent illness and slower recovery,
  • Low energy and a constant feeling of tiredness,
  • Anemia (i.e. dizziness, headaches, fatigue),
  • Irregular periods for women,
  • Premature births,
  • Slow growth for adolescents.

To prevent the diseases mentioned above, the essential nutrients must be obtained through the diet.

The benefits of being in healthy weight

Maintaining a healthy weight not only ensures good appearance but also increases your self-confidence, the efficiency in doing your daily activities, and, above all, keeps you away from health problems related to underweight or overweight.

A healthy lifestyle also ensures:

  • Fewer joint and muscle pains,
  • More energy and freedom to do your favorite activities,
  • Blood pressure is under control,
  • Less pressure on your heart and blood circulation,
  • Better sleep,
  • Lower risk of type II diabetes, heart disease, and certain cancers.

So if any of the health problems listed above are disturbing your life, there’s a good chance that getting your weight under control may be the best way to get rid of your troubles. But where exactly to start?

Now that you know your BMI...

Once you have calculated your body mass index and seen what category it falls into, you need to take action based on the result. If your BMI remained within normal weight, you do not need to make any significant changes – just continue with your current lifestyle and diet, assuming it is healthy and sustainable.

However, if your BMI is in the range of underweight, overweight, or even obesity, you should definitely start off by consulting with a nutritionist. This will give you a good overview of ​​your current state of health, and timely guidance from a specialist can help you alleviate or even prevent weight-related health problems.

In the case of overweight and obesity, in addition to booking a consultation appointment, you can also check out various weight loss surgeries, which have been life-changing journeys for hundreds of patients.

A remarkably easier and healthier life for you might be just around the corner!

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