BMI Calculator

The purpose of a BMI calculator is to provide your body mass index (BMI) and information on whether or not you have a healthy weight based on your age, height, and weight. With that information, you can implement the necessary changes to reclaim your health.

A body mass index calculator uses imperial units for those in the United States and the International System of Units (metric) for those living elsewhere. It’s easy to use and provides results as soon as you finish inputting the variables.

BMI Calculator

BMI Calculator


Unit of measurement *



What Is Body Mass Index (BMI)?

Body mass index (BMI) is a method of determining how lean or corpulent you are based on your height and weight. Its main purpose is to quantify tissue mass and act as a general indicator of whether or not you have a healthy body weight for your height.

The following are the formulae for calculating BMI based on the units:

  • For USC Units: BMI = {703 × (Mass in lbs/Height in inches squared)}
  • For Standard International System Units: BMI = Mass (kg)/Squared height (m)

After calculating BMI, the resultant value is used to categorize whether you are:

  • Underweight
  • Normal weight
  • Overweight
  • Obese.

It all depends on where the value lies. Our BMI calculator even informs you whether or not you’re healthy. The ranges of values of BMI that put you in one group or the other vary based on your age and region. These categories may further be subdivided into sub-categories like severely underweight and severely obese.

Being underweight or overweight has significant implications for your health. Despite being an imperfect determinant of healthy weight, it can ok indicate whether or not you need additional action or testing.

The World Health Organization (WHO) has developed a table showing recommended body weight based on BMI values for adults. It applies to men and women above 20 years. After using our BMI calculator, you can compare the results with the values in the table to see where you fall.

CategoryBMI Range (kg/m2)
Severe thinnessLess than 16
Moderate thinness16-17
Mild thinness17-18.5
Obese class I30-35
Obese class II35-40
Obese class IIIAbove 40

As a measure of healthy body weight, BMI is imperfect. It only provides an estimate and does not consider different body types, bone mass, muscle distribution, and fat BMI. Therefore, BMI works better when used with other measurements for determining healthy body weight.

How to Use a BMI Calculator

Our BMI calculator is straight and easy to use. It requires you to enter some variables and get results quickly. Here’s a step-by-step guide on properly is the calculator:

Step 1: Select the Unit of Measurement

The first step you must take to use our calculator is to select the unit of measurement you intend to use. There are two options – Metric and Imperial systems. The metric system is international and utilizes units such as meters and centimeters for height and kilograms for weight.

On the other hand, the Imperial System is older and mostly used in the United States. The units in this system are feet and inches for height and pounds for weight. Therefore, the choice of units of measurement depends on your location in the world.

Step 2: Enter Your Age

Age is a critical factor in determining your body mass index. As people grow older, they lead more sedentary lifestyles and accumulate more body fat. Older individuals also tend to have less muscle mass.

Therefore, your age is a critical variable. Enter it in the respective field. For our example, we entered 44 years for the age.

Step 3: Select Your Gender

The body weight composition in terms of fat and muscle varies between men and women. Therefore, men and women of the same age, height, and level of activity would have different BMIs. For the sake of illustration, we’ll use both sexes to see the results we’ll get.

Step 4: Enter Your Height

Next, you must enter your height. Shorter individuals tend to have their taller counterparts. Your height determines how much weight you can carry and remain healthy. You may enter height in centimeters using the metric system or in feet and inches using the Imperial System.

For our example, we chose male first and entered 165 centimeters and 62.25 kg in the height and weight fields using the metric system. We also entered 5 feet, 5 inches, and 138.33 pounds for the height and weight fields, respectively.

We also inputted some figures for the female option. We entered 165 centimeters and 67 kilograms for height and weight, respectively for the metric system. For the imperial system, we entered 5 feet, 5 inches for height, and 148.89 pounds for weight.

Step 5: Check the Results

Now you can go ahead and check out the results. The good thing about our calculator is that it provides results quickly. As soon as you finish entering the variables, the calculator will display the results. Here’s what we got from our calculation:

Measurement SystemAgeSexHeightWeightBMIHealth Status
Metric44 yearsMale165 cm62.25 kg22.9Healthy
Metric44 yearsFemale165 cm67 kg24.6Healthy
Imperial44 yearsMale5 ft, 5 in138.33 lbs23.0Healthy
Imperial44 yearsFemale5 ft, 5 in148.89 lbs24.6Healthy

Benefits of Using a BMI Calculator

A BMI calculator helps you to know whether or not you have a healthy weight. The following are the reasons why you should use it often.

1. Avoid the Risks of Being Overweight

Having excessive weight can expose you to the risk of serious health conditions and diseases. Once you discover that you have crossed the red line, you can take remedial measures to reduce your weight. For example, you can change your diet or become more active.

You’ll avoid diseases such as high blood pressure, type II diabetes, stroke, coronary heart disease, and gallbladder disease. Difficulty carrying excessive weight can expose you to joint and general body pain.

2. Mitigating the Risk of Low Body Mass

Having a low body weight is equally risky. It indicates serious health conditions, including malnutrition, osteoporosis, reduced immunity, hormonal imbalance, and increased risk of death. Therefore, once you get results from our BMI calculator, you can seek medical attention to discover the issues behind your excessive weight Loss.