BMI Calculator

Calculate your Body Mass Index (BMI) using our online BMI calculator for men and women. Determine your BMI value, see where you fall on the BMI chart, and identify your weight category—whether underweight, normal, overweight, or obese. This easy to read calculator also calculates the BMI Prime index, showing how close your BMI is to the upper healthy limit, and compares your weight to the optimal range for your height. Perfect for adults looking to manage their weight or assess health risks.

What Does the BMI Calculator Include?

BMI Value: Calculates your exact Body Mass Index.

BMI Category: Indicates your weight status (underweight, normal, overweight, or obese).

BMI Prime Index: Shows how close your BMI is to the upper healthy weight limit.

Optimal Weight Range: Displays how much you are overweight or underweight compared to the ideal weight range for your height.

How to Use the BMI Calculator

1. Choose Your Unit System
   Begin by selecting the unit system you prefer from the dropdown menu:
   • Metric (kg, cm): Input weight in kilograms and height in centimeters.
   • Imperial (lb, ft, in): Input weight in pounds and height in feet and inches.
2. Enter Your Height
   • Metric System: Enter your height in centimeters (e.g., 175 for 175 cm).
   • Imperial System: Enter your height in feet and inches in separate fields (e.g., 5 feet and 8 inches).
3. Enter Your Weight
   • Metric System: Input your weight in kilograms (e.g., 70 for 70 kg).
   • Imperial System: Input your weight in pounds (e.g., 150 for 150 lb).
4. Click “Calculate BMI”
   Once you’ve provided your height and weight, click the “Calculate BMI” button. The calculator will instantly process your data and display the results.
5. Review Your BMI Value
   Your BMI (Body Mass Index) will be displayed as a number calculated by dividing your weight by the square of your height:
   • BMI = Weight (kg) / [Height (m)]² for metric units.
   • BMI = [Weight (lb) × 703] / [Height (in)]² for imperial units.
6. Understand Your Weight Category
   The calculator provides your weight status (e.g., underweight, normal weight, overweight, or obese), based on your BMI value.
7. View the Optimal Weight Range
   The calculator will display the ideal weight range for your height. This range represents the weights that fall within the healthy BMI range of 18.5 to 24.9.
8. Check Your BMI Prime
   The BMI Prime value represents your BMI as a fraction of the healthy upper limit (25). A BMI Prime of less than 1 indicates a weight within the normal range, while a value above 1 indicates overweight or obesity.

This BMI calculator is a quick, easy and accurate way to assess your weight and health status. It works for adult men and women and uses established BMI standards to provide reliable and instant results.

Body Mass Index Chart

The BMI chart is a standard chart used to classify weight categories based on BMI values. It is applicable to adult men and women, giving you a quick and reliable way to determine if your weight is in a healthy range. Each category in the chart corresponds to a specific BMI range, helping you understand whether you fall into underweight, normal weight, overweight, or obesity classifications. The chart does not account for muscle mass or body composition, so it is most effective when used alongside other health assessments.

We made the chart mobile friendly so it’s easy to read when you’re at home or on the go at the gym.

How to Read the BMI Chart

1. Identify Your BMI Value
   Use the BMI calculator to determine your BMI. The value will be a number, such as 22.5 or 28.7.
2. Locate Your BMI Range
   Match your BMI value to the corresponding range in the chart:
   • If your BMI is 18.0, it falls under the Underweight category.
   • A BMI of 22.5 falls under the Normal Weight category.
   • A BMI of 30.5 is classified as Obese (Class I).
3. Understand Your Weight Category
   Each category in the chart corresponds to a specific weight classification:
   • Underweight: BMI less than 18.5.
   • Normal Weight: BMI between 18.5 and 24.9.
   • Overweight: BMI between 25 and 29.9.
   • Obese: BMI of 30 or above, divided into three classes.
4. Take Note of the Health Implications
   Use the chart to assess if your weight may pose health risks. For instance, being underweight or having a BMI in the obese range may indicate potential health concerns.

This chart serves as a helpful and easy visual guide for interpreting BMI results and understanding their implications for overall health.

Why is BMI Important?

1. Global Health Indicator
   Body Mass Index (BMI) is a standardized measure used worldwide to assess whether an individual’s weight is appropriate for their height. It provides a reliable way to classify weight categories, including underweight, normal weight, overweight, and obesity. This classification helps identify potential health risks related to weight.
2. Health Risk Assessment
   According to the World Health Organization (WHO), a high BMI is associated with an increased risk of non-communicable diseases such as cardiovascular disease, type 2 diabetes, and certain types of cancer. Conversely, a low BMI (underweight) is linked to malnutrition and weakened immunity.
3. Global Obesity Trends
   The Centers for Disease Control and Prevention (CDC) reports that obesity rates have been rising globally. In 2016, the WHO estimated that 39% of adults worldwide were overweight, and 13% were classified as obese. BMI serves as a critical tool in tracking and addressing these trends at both individual and population levels.
4. Universal Comparability
   BMI is a widely accepted metric because it uses a consistent formula: weight divided by the square of height. This allows comparisons across different countries, populations, and age groups (for adults). The global use of BMI helps in identifying public health priorities and implementing intervention programs.
5. Policy and Medical Guidelines
   Many countries use BMI as a criterion in medical guidelines for diagnosing weight-related conditions and determining eligibility for specific treatments or surgeries. For example, in bariatric surgery, BMI thresholds such as 40 or above (morbidly obese) are often prerequisites for eligibility.
6. Educational and Preventative Tool
   Governments, healthcare systems, and educational institutions use BMI as a screening tool to raise awareness about weight-related health risks. For instance, some schools in the United States use BMI assessments to track and promote healthy growth patterns among children.
7. Applicability in Developing Countries
   In low-income and developing countries, BMI is essential for identifying undernutrition and its associated health impacts. A low BMI is often used to measure the prevalence of malnutrition, especially among women and children, in these regions.

BMI is an essential metric globally, providing valuable insights into public health trends, individual health risks, and the need for medical or lifestyle interventions.

Why Use the BMI Calculator?

I created this calculator because, let’s face it, I’m getting older—well, not really old, but I’m creeping closer to 40. It hit me that I need to start paying attention to my health. Gone are the days of crushing pizza and chicken wings every day without a second thought. My health has never been more important than it is right now, and staying on top of it has become a priority.

This BMI calculator helps me track my weight and figure out if I’m on the right path. By calculating my BMI and understanding my weight category, I can take action when things start to slide. It’s not just about looking good; it’s about feeling better and making sure I’m here for the long haul. My goal is to live to 100, and keeping track of my BMI is one step in the right direction.

Using this calculator regularly keeps me accountable. Every month, I check my BMI to see how my current habits—whether good or bad—are affecting my weight. If the numbers start creeping into the wrong category, it’s my cue to adjust. This isn’t about being perfect; it’s about making small, manageable changes that add up over time.

I also wanted to make this calculator easy to use and visualize because I know firsthand how complicated health tracking can feel. All you need to do is input your height and weight, and you’ll instantly see your BMI, weight category, and even how far you are from your optimal weight range. It’s quick, straightforward, and gives you all the facts you need to make important decisions about your health.

For me, staying healthy is about more than just numbers—it’s about adding years to my life and life to my years. By using this BMI calculator and staying proactive about my weight, I feel like I’m giving myself the best shot at hitting that 100-year milestone. And who knows, maybe one day I’ll celebrate my 100th birthday with a slice of pizza—just in moderation this time!

Final Thoughts

If you’re like me and want to make the most out of life, tools like this BMI calculator can help you stay focused. It’s quick, it’s easy, and it works. So go ahead, give it a try, and take that first step toward a healthier you. You might even surprise yourself with how much you can achieve when you know exactly where you stand.

At the end of the day, health isn’t just about living longer—it’s about living better. And if this calculator can help you take control of your weight and health like it’s helped me, then it’s doing exactly what it was designed to do.