Free BMI Calculator

Calculate your Body Mass Index in seconds and get personalized health insights

Instant Results
WHO Standards
100% Free

Enhanced BMI Calculator

Get personalized health insights based on your BMI, age, and gender

Adding age provides more accurate health insights

Gender helps provide targeted recommendations

How to Use the BMI Calculator

Our BMI calculator is designed to be intuitive and user-friendly. Simply follow these steps to get accurate results in seconds. The calculator uses the standard BMI formula recognized by health organizations worldwide. Whether you prefer metric or imperial units, our tool automatically handles the conversions for you. No registration or personal information is required - just enter your measurements and get instant results.

1

Select your preferred unit system (Metric or Imperial)

💡 Pro Tip

For the most accurate results, measure your height and weight at the same time of day, preferably in the morning before eating.

What the BMI Calculator Calculates

The Body Mass Index (BMI) calculator provides a numerical value that represents your body weight in relation to your height. This value is calculated using the standard formula: weight divided by height squared. The calculator not only provides your BMI score but also categorizes it according to World Health Organization standards. You'll receive a detailed interpretation of your results, including whether you're underweight, normal weight, overweight, or in one of the obesity categories. Additionally, the calculator provides personalized health recommendations based on your results, ideal weight range for your height, and potential health risks associated with your BMI category. The tool is particularly useful for tracking weight management progress over time and understanding how your weight might be affecting your overall health.

Example Calculations

Healthy Adult Example

Input Values

weight:70
height:175
age:30
gender:male
units:metric

Result

22.9

This BMI of 22.9 falls within the normal weight range (18.5-24.9), indicating a healthy weight for this height.

Athletic Build Example

Input Values

weight:85
height:180
age:28
gender:male
units:metric

Result

26.2

BMI of 26.2 is classified as overweight, but for athletes with high muscle mass, BMI may not accurately reflect health status.

Weight Loss Goal Example

Input Values

weight:95
height:165
age:35
gender:female
units:metric

Result

34.9

BMI of 34.9 indicates Class I obesity. A 15-20kg weight loss would bring BMI to the healthy range.

💡 Understanding Your Results

These examples show typical scenarios. Your individual results may vary based on factors like muscle mass, bone density, and overall health. Always consult with healthcare professionals for personalized advice.

Frequently Asked Questions

BMI (Body Mass Index) is a simple calculation using height and weight to estimate body fat. It's important as a screening tool to identify potential weight-related health risks, though it doesn't directly measure body fat or overall health.

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BMI Formula & Scientific Background

Understanding the mathematical foundation behind BMI calculations

Metric:BMI ​=​ weight ​(​kg​)​ ​÷​ height² ​(​m²​)​
Imperial:For imperial units: BMI ​=​ ​(​weight in pounds ​×​ 703​)​ ​÷​ ​(​height in inches​)​²

Formula

BMI ​=​ weight ​(​kg​)​ ​÷​ height² ​(​m²​)​

Metric Formula

BMI ​=​ weight ​(​kg​)​ ​÷​ height² ​(​m²​)​

Imperial Formula

BMI ​=​ ​(​weight in pounds ​×​ 703​)​ ​÷​ ​(​height in inches​)​²

Scientific Background

BMI was developed by Belgian polymath Adolphe Quetelet in the 1830s, originally called the 'Quetelet Index.' The World Health Organization adopted BMI as the standard for recording obesity statistics since the early 1980s. While useful for population studies, BMI has limitations for individual assessment as it doesn't account for muscle mass, bone density, or fat distribution.

Medical Disclaimer

This BMI calculator is for informational purposes only and is not intended to replace professional medical advice, diagnosis, or treatment. BMI is a screening tool and may not be accurate for all individuals, particularly athletes, elderly, or those with high muscle mass. Always consult with a qualified healthcare provider before making any decisions about your health or fitness.