Calculate Your BMI
Enter your height and weight to calculate your body mass index, see your adult BMI category, and understand what your result may mean.
Enter Your Details
Choose your measurement system and enter your current measurements.
Your BMI Result
Where Your BMI Falls
Adult BMI categories are screening ranges used to help interpret weight in relation to height.
Reference Range for Your Height
This is a BMI-based reference range, not a personalized target weight.What This Result May Mean
What Your BMI Result Can — and Cannot — Tell You
BMI Can Help Show
- Your weight relative to your height
- Your standard adult BMI category
- Changes in BMI when your weight changes
- A starting point for a health discussion
BMI Does Not Directly Measure
- Body fat percentage
- Muscle or bone mass
- Waist size or fat distribution
- Fitness or overall health
Helpful Guides to Read Next
These resources are selected based on your BMI category to help you understand the result beyond the number.
Some People Need More Context Than BMI Alone
Was This Calculator Helpful?
Your feedback helps us improve our calculator and create a better experience for everyone who uses BMIBox. If your result was clear and useful, we’d appreciate a quick review.
BMI is a screening tool, not a diagnosis. It does not directly measure body fat, muscle mass, waist size, fitness, or overall health. Your result should be considered with other health information. Speak with a qualified healthcare professional when you need personal guidance about your weight or health.
BMI Categories
Compare the standard BMI ranges used to classify underweight, healthy weight, overweight, and obesity.
Underweight
Below the standard healthy-weight BMI range for adults.
Healthy Weight
Within the standard healthy-weight BMI range for adults.
Overweight
Above the standard healthy-weight BMI range for adults.
Obesity
Within the standard adult obesity BMI range.
Must Read Articles
What to Do If Your BMI Is High
Learn what to do if your BMI is high, how to check waist size and health markers, and when to speak with a healthcare professional
What BMI Is Considered Obese?
Learn what obese BMI means, the BMI 30+ range, obesity classes, health context, waist size, and why BMI is not a diagnosis.
When BMI Can Be Wrong?
Learn when BMI can be wrong, why BMI may misread athletes, seniors, pregnancy, ethnicity, and muscle mass, and what to check instead
BMI Calculator FAQs
Find quick answers about how the BMIBox calculator works, what your BMI result means, and where body mass index has limitations.
Is the BMI calculator free?
Yes. The BMIBox BMI calculator is free to use and does not require an account or registration. Enter your height and weight to receive an adult BMI result and standard BMI category. The result is educational and should not be treated as a medical diagnosis.
Is this BMI calculator for adults?
Yes. The calculator is designed for adults aged 20 and older. Standard adult BMI ranges are not suitable for children or teenagers, who are assessed using BMI-for-age percentiles. The calculator is also not intended to interpret weight changes during pregnancy.
What is a healthy BMI?
For most adults, a BMI from 18.5 to 24.9 is classified as the healthy weight range. This range is used for general screening. It does not guarantee good health because BMI does not measure body fat, waist size, blood pressure, blood sugar, fitness, or medical history.
Is BMI accurate?
BMI is accurate as a height-to-weight calculation, but it is limited as a measure of individual health. It cannot distinguish fat from muscle or show where body fat is stored. It may be less useful for athletes, muscular adults, older people, pregnant adults, and some ethnic groups.
Learn more about BMI accuracy →Can BMI be high because of muscle?
Yes. Muscle adds weight, and BMI cannot tell whether that weight comes from muscle or body fat. Athletes and muscular adults may receive a higher BMI result even when their body fat level is relatively low.
Read how BMI applies to athletes →Should I use BMI or body fat percentage?
The two measurements answer different questions. BMI compares weight with height, while body fat percentage estimates how much of the body consists of fat. Neither measurement is perfect. Using BMI with waist size, body composition, and health information may provide better context.
Compare BMI and body fat percentage →Does BMI diagnose obesity or another health condition?
No. BMI places adults into standard screening categories, including obesity ranges, but the calculation does not diagnose a disease or confirm a person’s overall health. Diagnosis and personal medical assessment should come from a qualified healthcare professional.
Understand the limitations of BMI →