BMI Calculator
Calculate your Body Mass Index based on your height and weight to check if you're in a healthy weight range
Units
Your BMI Result
Enter your height and weight to calculate your BMI
What is BMI?
Body Mass Index (BMI) is a value derived from the mass (weight) and height of a person. The BMI is defined as the body mass divided by the square of the body height, and is expressed in units of kg/m².
How is BMI calculated?
BMI is calculated using the formula: BMI = weight(kg) / (height(m))². For those using imperial units, the formula is: BMI = (weight(lbs) * 703) / (height(in))².
Healthy BMI Range
A BMI of 18.5 to 24.9 is considered healthy for most adults. A BMI below 18.5 indicates underweight, 25-29.9 indicates overweight, and 30 or above indicates obesity.
Limitations of BMI
While BMI is a useful tool for identifying potential weight problems in adults, it has limitations. It doesn't account for factors like muscle mass, bone density, or body fat distribution. Athletes may have a high BMI due to muscle mass rather than body fat.
What to do with your BMI result
If your BMI falls outside the healthy range, consider consulting a healthcare professional for personalized advice. Remember that BMI is just one indicator of health and should be considered alongside other factors.
Understanding BMI and Its Importance
Body Mass Index (BMI) is a widely used screening tool that helps assess whether a person has a healthy body weight in relation to their height. Developed in the 1830s by Belgian mathematician Adolphe Quetelet, BMI has become a standard method for preliminary evaluation of weight status. While BMI cannot directly measure body fat or overall health status, it provides a simple and quick way to categorize individuals into weight groups that may indicate increased risk for health problems. Regular BMI monitoring can help track weight changes over time and serve as a starting point for discussions with healthcare providers about achieving or maintaining a healthy weight.
How to Use Our BMI Calculator
Select Your Preferred Units
Choose between metric (centimeters/kilograms) or imperial (feet/pounds) measurement systems based on your preference.
Enter Your Height
Input your height in either centimeters or feet and inches, depending on your selected unit system.
Enter Your Weight
Input your current weight in either kilograms or pounds, matching your chosen unit system.
Calculate Your BMI
Click the 'Calculate BMI' button to instantly see your Body Mass Index and which category your result falls into.
Interpret Your Results
Review your BMI category and the associated description to understand what your result means for your health.
What Users Say About Our BMI Calculator
Health Conscious User
I use this BMI calculator weekly to track my weight management progress. It's simple to use and gives me the information I need without complications.
Fitness Trainer
I recommend this BMI calculator to my clients as a starting point for their fitness journey. The clear categories help them understand where they stand.
Medical Professional
This is a useful screening tool I suggest to patients who want to monitor their weight between appointments. I appreciate the educational content that explains BMI limitations.
Features of Our BMI Calculator
Dual Unit System
Switch between metric and imperial units based on your preference or location.
Instant Calculation
Get immediate results with our responsive calculator that works on all devices.
Category Classification
See which weight category your BMI falls into: underweight, normal weight, overweight, or obese.
Educational Information
Learn about BMI, its calculation method, limitations, and how to interpret your results.
Privacy-Focused
All calculations happen in your browser — no personal data is sent to our servers or stored.
Frequently Asked Questions About BMI
Is BMI accurate for everyone?
BMI is not equally accurate for all individuals. It may overestimate body fat in athletes and others with muscular builds, while underestimating body fat in older persons or those who have lost muscle mass. BMI should be considered alongside other measurements and health indicators.
How often should I calculate my BMI?
For general health monitoring, calculating your BMI every 1-3 months is usually sufficient. More frequent calculations might be appropriate if you're actively working on weight management under professional guidance.
Are BMI categories the same for all ages and genders?
Standard BMI categories are generally the same for adult men and women. However, interpretations may vary for children and teens (who should use age and gender-specific BMI charts), pregnant women, elderly individuals, and across different ethnic groups.
What should I do if my BMI indicates I'm overweight or obese?
If your BMI falls into the overweight or obese category, consider consulting with a healthcare provider. They can perform additional assessments, discuss potential health risks, and help develop an appropriate plan that may include dietary changes, increased physical activity, and other lifestyle modifications.
Can BMI be used to diagnose health problems?
BMI alone cannot diagnose health problems or body fatness. It's best used as a screening tool to identify potential weight issues. Healthcare providers typically use BMI along with other assessments—such as skinfold thickness measurements, evaluations of diet, physical activity, family history, and other health screenings—to evaluate overall health status.