BMI (Body Mass Index) is a measure of body fat based on an individual's weight in relation to their height. It is calculated by dividing weight by height squared and is used as a screening tool to identify potential health risks.

How do I calculate BMI?

BMI is calculated using the formula: BMI = weight (kg) / height² (m²). For imperial units: BMI = (weight × 703) / height². You can use our free BMI calculator for accurate results.

When should I not use BMI?

BMI may not be accurate for athletes, elderly individuals, pregnant women, children, and people with certain medical conditions. It doesn't account for muscle mass, bone density, age, sex, or ethnicity.

BMI Calculator

A Body Mass Index Calculator to check your BMI below! Recognized as a better way to see if a person is overweight / underweight based on height and weight.

Note: Accuracy can vary for people such as athletes, children, the elderly, endomorphic or ectomorphic frames.

Calculate Your BMI

Your BMI Result

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Enter your weight and height to calculate your BMI

BMI Categories

Underweight< 18.5

Normal weight18.5 - 24.9

Overweight25.0 - 29.9

Obese≥ 30.0

BMI Formula

BMI = weight (kg) / height² (m²)

Metric: weight in kilograms, height in meters

Imperial: weight in pounds, height in inches

* For imperial units: BMI = (weight × 703) / height²

Health Recommendations

For Underweight (BMI < 18.5)

• Increase caloric intake with healthy foods
• Include strength training exercises
• Eat more protein-rich foods
• Consider consulting a nutritionist

For Normal Weight (BMI 18.5-24.9)

• Maintain current healthy lifestyle
• Regular exercise and balanced diet
• Monitor weight regularly
• Stay hydrated and get adequate sleep

For Overweight (BMI 25-29.9)

• Reduce caloric intake gradually
• Increase physical activity
• Focus on whole foods
• Consider professional guidance

For Obese (BMI ≥ 30)

• Consult healthcare professional
• Create structured weight loss plan
• Regular medical monitoring
• Consider behavioral therapy

Important Notes

BMI Limitations: BMI is a useful screening tool but has limitations. It doesn't directly measure body fat or account for muscle mass, bone density, age, sex, and ethnicity.

Athletes: Muscular individuals may have a high BMI despite having low body fat.

Elderly: BMI may underestimate health risks in older adults due to muscle loss.

Children: BMI interpretation for children requires age and sex-specific growth charts.

Consultation: Always consult with healthcare professionals for personalized health advice.

What is BMI?

A BMI calculator is a tool that is used to estimate an individual's body mass index (BMI) based on their height and weight. BMI is a measure of body fat based on an individual's weight in relation to their height. It is widely used as a screening tool to identify potential health risks associated with obesity and being underweight.

BMI is calculated by dividing an individual's weight by their height squared. The resulting number is then compared to a standard BMI chart to determine the individual's BMI category, such as underweight, normal weight, overweight, or obese.

Our BMI calculator is easy to use and requires only basic information: Your height and weight, and our calculator will give you an estimated BMI.

However, it's important to note that BMI calculators are not always accurate and should be used as a screening tool rather than a diagnostic tool.

When NOT to use BMI?

Here are some examples of when BMI may not be the best tool to use:

Athletes and bodybuilders: BMI does not take into account muscle mass, so individuals who are very muscular may have a high BMI even though they are not overweight or obese.

Elderly individuals: BMI may underestimate body fat in older individuals who have lost muscle mass, which is a common occurrence with aging.

Pregnant women: BMI is not a reliable measure of body fat in pregnant women because it does not account for the weight of the fetus or the increased fluid and blood volume during pregnancy.

Children: BMI charts for children and adolescents take into account age and sex as well as height and weight, but they still may not be an accurate measure of body fat in growing children.

Individuals with certain medical conditions: BMI may not be a reliable indicator of health in individuals with certain medical conditions, such as those with muscular dystrophy or those who have undergone amputations.

In these cases, other measures of body fat, such as skinfold thickness, bioelectrical impedance, or dual-energy x-ray absorptiometry (DXA), may be more appropriate.

It is always best to consult with a healthcare professional to determine the most appropriate method of assessing body fat for individual cases.

How to use our BMI Calculator

Using a BMI (body mass index) calculator is a simple and straightforward process. Here are the steps to follow:

Enter your height. You will need to enter your height in either centimeters or feet and inches, depending on what units you use.
Enter your weight. You will need to enter your weight in either kilograms or pounds.
Calculate your BMI. Once you have entered your height and weight, click the "Calculate" button to see your BMI.
Review your results. Your BMI will be displayed on the screen, along with an interpretation of what it means. You will also see your BMI category: underweight, normal weight, overweight, or obese.

BMI Results

BMI Score	Category	Suggested Steps
Below 18.5	Underweight	If you are underweight, it is important to consult a doctor or a dietitian to develop a healthy eating plan and gain weight in a safe and sustainable way. This may involve consuming more protein, healthy fats, and complex carbohydrates to increase your calorie intake, as well as engaging in strength training exercises to build muscle mass.
18.5 - 24.9	Normal	Maintaining a balanced diet and engaging in regular physical activity are key to staying healthy and preventing weight-related health issues. Eat plenty of fruits, vegetables, whole grains, lean proteins, and healthy fats, and aim for at least 30 minutes of moderate-intensity exercise most days of the week.
25.0 - 29.9	Overweight	If you are overweight, reducing your calorie intake and increasing your physical activity levels can help you achieve a healthy weight and reduce the risk of health problems. This may involve eating a balanced, low-calorie diet that is rich in whole foods and low in processed and high-fat foods, and engaging in regular aerobic and strength training exercises to burn calories and build muscle.
Above 30.0	Obese	If you are obese, it is important to consult a doctor or a dietitian to develop a weight loss plan that includes diet modifications, physical activity, and possibly medication or surgery to reduce health risks associated with obesity. This may involve eating a low-calorie, nutrient-rich diet that is high in fruits, vegetables, lean proteins, and healthy fats, and engaging in regular aerobic and strength training exercises to burn calories and build muscle.

History of BMI

Did you know... BMI (Body Mass Index) was developed by Adolphe Quetelet, a Belgian statistician, astronomer, and mathematician, in the early to mid-19th century.

Quetelet was interested in developing a simple, standardized way to measure obesity in populations.

He recognized that simply measuring body weight was not sufficient, as taller individuals would naturally weigh more than shorter individuals, even if they had the same amount of body fat.

BMI (body mass index) is sometimes called the "Quetelet Index" after its developer, Adolphe Quetelet.