BMI Calculator - Calculate Your Body Mass Index

In the BMI calculator, weight, height, age, and gender serve as essential input parameters. You can input your weight and height to determine your body mass index, a measure used to assess body fat based on these physical attributes.

Calculate Your BMI

Introduction to BMI

What is a BMI calculator, and why is it used? When gauging your health, relying solely on your weight can be misleading. After all, it does not consider important factors like height and body composition. Picture this: a tall, lean individual might weigh more than a shorter but chubby person. Yet, the former may be in better health.

So, where do you lie on the wellness scale? A body mass index can solve this query. It is a criterion that helps measure your body mass index. Let’s delve deeper into the height weight chart, BMI and how it is calculated.

What is BMI?

The full form of BMI is Body Mass Index. It is a numerical measure that assesses an individual’s body weight in relation to their height. Deviating from the recommended ratio can increase the risk of chronic healthcare complications in future. Although BMI is not the only factor individuals rely on when assessing their health and fitness, it is a significant starting point.

What is a BMI Calculator?

A BMI calculator is an online tool or software that lets individuals quickly compute their body mass index. It measures the body mass a person has in proportion to their height and weight. The tool provides a snapshot of an individual’s overall physical health. It can help understand if you are underweight, healthy weight, overweight, or obese.

How to Use Our BMI Calculator?

If you are wondering, "Can I calculate my BMI?" the answer is yes, you can with just a few clicks. Using a body mass index calculator is a simple process. Here are the steps to follow:

  1. Gather Your Measurements: You can compute your BMI with accurate height and weight values. If you have the measurements in feet or inches, convert them into metric units (centimetres and kilograms).
  2. Access the BMI Calculator: Choose a calculator from a trusted health-related website like HexaHealth.
  3. Input Your Data: Enter your weight and height into the provided fields. Make sure you select the appropriate units as specified by the calculator.
  4. Calculate Your BMI: After inputting your data, click the "Calculate" or "Check BMI" button on the calculator. The tool will perform the necessary calculations.

Limitations of BMI

Body mass index is used for assessing general health, but it has several limitations. It does not take body composition into account. Therefore, BMI should be used alongside other health indicators and not as a sole method. The limitations of BMI include:

  1. Lack of Precision: It does not differentiate between muscle and fat. People with a high muscle mass may have a higher BMI, even low body fat, leading to potential misclassifications.
  2. Gender Differences: The height weight chart used for adults assigned male at birth (AMAB) is the same as for adults assigned female at birth (AFAB). However, adults AFAB typically have a higher percentage of body fat than adults AMAB.
  3. Does Not Measure Central Obesity: It does not consider fat distribution in the body. Central or abdominal obesity (fat concentrated around the abdomen) is a significant risk factor for health issues like heart disease and diabetes. BMI doesn’t capture this information.
  4. Unaccounted Other Factors: The relationship between Body Mass Index and mortality risk often fails to consider key factors. These include a family history of diabetes or cancer, cardiovascular disease, high blood pressure, and familial longevity (average lifespan).
  5. Ignores Body Composition: A standard BMI chart should not be used to assess body fat for athletes, muscular people, and older adults (over 65). They may have a higher body mass than others due to increased muscle volume or age-related changes in the body.
  6. Limited for Children: BMI fails to consider a child’s growth rate and maturity. While it can effectively identify obese children, it may not accurately detect overweight children. A slightly elevated Body Mass Index could be attributed to increased fat-free mass rather than excess body fat.

How to Calculate Your BMI?

If you are wondering, "How to calculate BMI with height and weight?" you should know that it is pretty simple. You can use the Body Mass Index formula to know if you have an ideal BMI or not.

BMI Calculation Formula

You can obtain the BMI by putting weight and height measurements into the formula. It can be calculated using two methods:

  1. Metric System
  2. English System

Metric System

It uses a BMI calculator in kg and metres (weight in kgs and height in metres). If you know your height in centimetres, divide the number by 100 to convert it into metres. The BMI formula is as follows:

BMI = Weight (kg) / [Height (m)] 2

English System

Knowing your weight in pounds and height in inches, you can calculate BMI using the English system. It requires dividing the weight by the squared height and multiplying the amount by 703. The BMI calculation formula for the English system is as follows:

BMI = Weight (lb) / [Height (in)] 2 X 703

You can also use our BMI calculator to determine your BMI instantly.

Body Mass Index (BMI) Chart

A BMI chart is a graphical or tabular representation that provides the BMI classifications with corresponding height and weight. A height and weight chart according to age is as follows:

Adults (Age 20+)

BMI interpretation for adults aged 20 and above relies on standardised weight status categories. These are generally the same for men and women and include all body types and age groups.

bmi chart

Children and Teens (Ages 2 to 19)

For children and teens, BMI interpretation differs from the standard approach despite being calculated using the same formula. It necessitates age and gender specific considerations because body fat levels change according to age and gender. The BMI chart for children and teens aged 2 to 19 shows BMI as a percentile ranking.


girls bmi chart


boys bmi chart

Interpreting Your BMI Results

Calculating the BMI does not provide all the answers. It is important to understand what Body Mass Index represents. The following section provides valuable insights into making sense of your BMI results for an adult or a child.

BMI Categories

BMI categories are a classification system used to assess an individual’s weight status based on their value. The standard categories for adults are as follows:

  1. Underweight: These individuals are advised to gain weight for attaining appropriate health index.
  2. Healthy Weight: People in this category have a healthy weight for their height. They have a significantly lower risk of serious health conditions.
  3. Overweight: Individuals are slightly overweight than the ideal level. They should lose some weight to prevent health conditions.
  4. Obese: This category includes people with abnormal fat accumulation. There may be a risk to their health if they do not lose weight.

What Does Your BMI Mean for Your Health?

The calculated BMI may signify one of the above categories. The interpretation differs between adults and children. Once you calculate your Body Mass Index, it can be interpreted as follows for adults above 20 years:


Weight Status Category

Below 18.5


18.5 to 24.9

Healthy weight

25.0 to 29.9


30.0 and above


BMI for children and teens aged 2-20 is classified using percentiles obtained from the chart. Percentiles are a measure that assesses where a child stands compared to a group with similar characteristics, such as age and gender. The interpretation is as follows:

Percentile Range

Weight Status Category

Less than the 5th percentile


5th percentile to less than the 85th percentile

Healthy weight

85th percentile to less than the 95the percentile


Equal to or greater than 95th percentile


Ideal BMI for Men and Women

If you are experiencing low energy, it could indicate an imbalance in your body fat corresponding to height and weight. Understanding your BMI is a valuable tool to determine whether you belong to the underweight or obese category.

A BMI calculator for men and women can help individuals determine their Body Mass Index. An ideal or normal BMI, irrespective of gender, is considered from 18.5 to 24.9.

BMI Calculator for Pregnant Women

Your pre-pregnancy BMI determines the recommended weight gain during pregnancy. It uses your height to weight ratio to calculate body fat. The weight gain recommendations during pregnancy are as follows:

BMI before Pregnancy

One Baby


Less than 18.5 (underweight)

28-40 pounds

50-62 pounds

18.5-24.9 (normal weight)

25-35 pounds

37-54 pounds

25-29.9 (overweight)

15-25 pounds

31-50 pounds

Equal to or above 30 (obese)

11-20 pounds

25-42 pounds

Ideal BMI for Children

A child BMI calculator works differently from those of adults. Why, you ask? This is due to the fluctuation in body fat levels as children grow. Age and gender are crucial factors that affect the ideal BMI for children and teens aged 2 to 19.

Each child’s BMI is compared to percentiles specific to children of the same sex and age. An ideal Body Mass Index for children ranges between the 5th percentile and below the 85th percentile.

Using BMI to Track Your Progress

Tracking your BMI can be a key component in achieving your health goals. It helps assess the effectiveness of your lifestyle changes, weight management efforts, and overall well-being.

Setting Goals and Making Healthy Changes

The first step in achieving a normal BMI is consulting a doctor for an ideal weight loss goal. The doctor will determine your medical history, make personalised recommendations, and refer you to a nutritionist.

It is recommended to set process goals (walking 10,000 steps every day or five servings of vegetables each day) rather than outcome goals (losing 14 kgs). One effective way to lose weight is by setting SMART goals. For example:

  • Specific: "I will walk 10,000 steps 6 times a week."
  • Measurable: "I want to lose 1 kg this week and track my progress."
  • Achievable: "I will aim to lose 0.4 to 1 kg per week, which is a safe and realistic rate of weight loss."
  • Relevant: "I will focus on a balanced diet and exercise routine that suits my lifestyle and preferences, aligning my weight loss goals with my overall health objectives."
  • Time-Bound: "I will reach my goal of losing 4.5 kgs in 10 weeks."

Health Risks Related to Being Overweight

A BMI of 25 to 29.9 is interpreted as overweight. People with a Body Mass Index from 30 to 40 are obese, and those with a BMI above 40 are severely obese. Being overweight or obese elevates the risk of various health issues and complications, including:

  • Heart disease
  • Liver disease
  • High blood pressure
  • Diabetes
  • Stroke
  • Osteoarthritis
  • Gallstones
  • Sleep apnoea
  • Atherosclerosis (buildup of cholesterol deposits in blood vessels)
  • Cataract
  • Hernia

Health Risks Related to Being Underweight

Being underweight is as unhealthy as being overweight or obese. People with a BMI below 18.5 are in the underweight category. Those below 15 are considered severely underweight. Health risks and complications of being underweight or malnourished include:

  • Bone loss
  • Heart problems (like irregular heart rhythms)
  • Decreased immune function
  • Iron deficiency anaemia
  • Fertility issues in women
  • Growth and development issues in children
  • Depression and anxiety

Tips for Improving Your BMI and Overall Health

Once you know the BMI category you fall into, it is important to improve your overall health. Whether you are looking to lose or gain weight or maintain a balanced BMI, the following lifestyle changes can help:

  • Eating a Healthy Diet: Focus on a balanced diet, including fruits, vegetables, whole grains, and more. Reduce the consumption of calories, alcohol, sugar, processed foods, and juices.
  • Exercise Regularly: Include regular physical activity in your routine. Aim for a mix of cardio and weight-bearing exercises to build muscle and lose belly fat.
  • Portion Control: Be careful with portion sizes. Avoid overeating during meals and snacks.
  • Other Lifestyle Changes: Maintain hydration, ensure quality sleep, track progress, and seek professional guidance to improve your BMI.


The BMI calculator is a vital tool for anyone looking to evaluate their weight and health status. It offers a convenient method to know your BMI and initiate discussions about overall well-being. So, don’t hesitate to calculate your body mass index and take the first step toward a healthier you.

You can also consult experts at HexaHealth to know more about your BMI. Our team of experts will use a height weight chart to help you determine your BMI. They will also provide expert tips to achieve the ideal lifestyle for adults and children. Contact us TODAY!

Frequently Asked Questions (FAQ)

What is a BMI calculator?

A BMI calculator is a tool that assesses an individual’s health by calculating their Body Mass Index (BMI), using weight and height. It categorises them into underweight, normal weight, overweight, or obese based on the result. 

How to use a BMI calculator?

Using a BMI calculator is simple. Input your weight and height, select the appropriate units (kilograms and metres or pounds and inches), and click Calculate. The tool then computes your BMI. It uses the height weight chart to place you in a category, such as underweight, normal weight, overweight, or obese.

What is the BMI formula?

The BMI formula is BMI = weight (kg) / [height (m)] 2. Alternatively, it can be calculated as BMI = weight (lb) / [height (in)] 2 X 703 when using pounds and inches. The formula assesses body weight concerning height.

Can you explain the BMI full form?

The BMI full form is Body Mass Index. It is a numerical measure that assesses an individual’s body weight relative to height.

How accurate is BMI for health?

Body mass index is a useful tool for assessing general health and identifying potential health risks. However, it has limitations, such as not accounting for factors like muscle mass or body composition. Therefore, while it provides a basic indication of health, it should be used with other assessments for a complete evaluation.

Where can I find a body mass index calculator?

You can find a body mass index calculator easily online curated by HexaHealth professionals. Visit our website for the same and to gain all kinds of healthcare assistance. You can also manually calculate your BMI using the BMI formula.

What is the BMI calculation formula?

The BMI calculation formula is as follows:

BMI = weight (kg) / [height (m)] 2 (metric system)

BMI = weight (lb) / [height (in)] 2 X 703 (English system)

How to use a BMI calculator in kg?

To use a BMI calculator in kg, input your weight in kilograms and height in metres, then click Calculate. The calculator will use the formula for BMI to compute your body mass index.

Is there an ideal weight calculator based on BMI?

Yes, there is an ideal weight calculator to determine healthy body weight based on an individual's physical attributes. However, the calculator is not solely based on BMI as it does not consider individual factors. BMI cannot state how much a person should weigh to fall in the healthy range.

Can you explain the height to weight ratio in BMI?

The height to weight ratio in BMI calculates an individual’s body mass in relation to their height. It provides a numerical value indicating whether a person’s weight is appropriate for their height.

What is the significance of body mass index?

The significance of body mass index lies in its ability to offer a quick assessment of an individual’s health and weight status. By categorising them as underweight, healthy, overweight, or obese, BMI helps make informed decisions about overall well-being.

Is there a BMI calculator by age?

Yes, there is a BMI calculator by age, one for adults above 20 years and another for children and teens (2-19 years). BMI for children and teens is assessed using age and gender-specific percentiles. This accounts for changing body composition with age.

Where can I find a height and weight chart according to age?

You can find height and weight charts according to age for children and adolescents through reputable healthcare websites and paediatric clinics. These charts help monitor growth and development in young individuals. You can also talk to experts at HexaHealth to understand BMI.

How do I use a BMI calculator for men?

You can use a BMI calculator for men by inserting your weight in kilograms and height in metres. After clicking Calculate, the tool will interpret your BMI results.

Are there specific BMI calculators for women?

No, there are no specific BMI calculators for women or men. The calculation is based on weight and height and is the same for all adults regardless of gender.

How can I calculate my BMI?

If you are wondering, How to calculate my BMI ? use this formula: BMI = weight (kg) / [height (m)] 2 . Several online calculators are also available to simplify the process.

Is there a BMI calculator specific to India?

No, there is no specific BMI calculator for India or other countries. BMI calculators are universal and apply to all countries. They are based on the same formula of weight and height, regardless of geographical location. 

How can I calculate BMI for children?

Calculating BMI for children involves using the same formula as for adults. However, for children, the result is compared to age- and sex-specific percentiles to determine their BMI category. 

What is the method to calculate BMI using height and weight?

If you are wondering how to calculate BMI with height and weight, use this formula: BMI = weight (kg) / [height (m)] 2 . The result categorises individuals into underweight, healthy, overweight, or obese.

Is there a body fat calculator associated with BMI?

Body mass index is not a direct measure of body fat. While BMI assesses body weight relative to height, it does not differentiate between muscle and fat. A separate body fat calculator estimates body fat percentage more accurately.

Where can I find a body fat percentage calculator?

You can find body fat percentage calculators online through health and fitness websites. Always ensure the calculator is reputable and based on validated methods for accurate results.

When should I be concerned with my child weight?

A child’s weight becomes a concern when their BMI is high. Children with a strong and muscular build are not at risk of health concerns if their BMI is normal. If a child has a BMI over the 95th percentile, they are considered to have obesity. Consult a doctor for guidance.

When should I start checking my BMI?

BMI can be used to detect overweight and obesity in children beginning at two years.

What is my ideal weight?

Your ideal weight depends on height, age, gender, and overall health. It is best determined through consultation with a doctor or registered dietitian. They consider your circumstances and goals.

What is my child ideal weight?

A child’s ideal weight varies depending on age, gender, and growth. It is best determined by comparing their growth pattern and body composition to standard growth charts. Consult with a paediatrician or doctor for guidance.

Does BMI account for muscle?

BMI does not differentiate between muscle and fat. It assesses weight relative to height. Individuals with high muscle mass may have a higher Body Mass Index, even when their body fat percentage is low.

How can I help my child reduce his or her BMI?

To help your child reduce their BMI, focus on the following:

  • Promote a balanced diet with age-appropriate portions
  • Encourage physical activity
  • Keep them hydrated
  • Track progress
  • Consult a paediatrician or registered dietitian for personalised guidance.

How long will it take to reduce BMI?

The time it takes to reduce BMI depends on individual factors, including starting BMI, weight loss goals, diet, and exercise. A gradual and sustainable approach, losing 0.45 to 1.36 kg per week, is generally recommended for healthy and lasting results. Consult a specialist or registered dietitian to create a personalised plan and set realistic expectations.

What is the line of treatment if BMI is between 27 to 32?

If your BMI falls between 27 and 32, it is considered overweight. The treatment typically involves lifestyle changes such as a balanced diet and increased physical activity. Consult a specialist for personalised guidance.

What is the line of treatment if BMI is between 32 to 40?

If your BMI is between 32 and 40, it falls in the obese range. Treatment involves comprehensive lifestyle changes, including dietary modifications, increased physical activity, and medical interventions. Consult a medical specialist for a personalised plan and guidance.

What is the line of treatment if BMI is above 40?

When BMI is above 40, it is categorised as severe obesity. Treatment may involve more intensive interventions, such as bariatric surgery, lifestyle changes and medications. Consult your doctor to discuss the most appropriate treatment plan for your situation.

What are the limitations of an online BMI Calculator?

The limitations of an online BMI calculator are as follows:

  • Lack of muscle and fat differentiation
  • Ignores central obesity
  • Overlooks body composition
  • Limited use for children

What are the alternate estimates of weight-related health risks?

Alternatives to BMI for assessing weight-related health risks include:

  • Waist circumference
  • Waist-to-hip ratio
  • Waist-to-height ratio

How Often to Calculate Your BMI?

It is generally recommended to check your BMI three to four times annually. This allows you to record your physical well-being and sustain a healthy lifestyle.

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