Body Mass Index (BMI) is a simple numerical value of a person’s weight in relation to their height. It is a widely used screening tool to categorize individuals as underweight, normal weight, overweight, or obese.

Is BMI the same for men and women?

The standard BMI formula is the same for both adult men and women. However, it's important to note that men often have more muscle mass than women, and muscle is denser than fat, which can occasionally lead to a higher BMI even with low body fat.

What are the BMI categories?

According to the World Health Organization (WHO): Underweight is less than 18.5; Normal weight is 18.5–24.9; Overweight is 25–29.9; and Obese is 30 or greater.

How accurate is BMI as a health indicator?

While BMI is a useful screening tool, it has limitations. It does not directly measure body fat or distribution. Athletes with high muscle mass may have an 'overweight' BMI despite being very healthy, while older adults with low muscle mass may have a 'normal' BMI despite having high body fat.

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Health & Fitness

BMI Calculator – Healthy Weight Range Service | CalcTools

Calculate your Body Mass Index (BMI) to determine if you are in a healthy weight range based on your height and weight. Works for both metric and imperial units.

Maintaining a healthy weight is a critical component of overall well-being and longevity. One of the most common and accessible tools used by healthcare professionals worldwide to assess weight status is the Body Mass Index, or BMI. This simple numerical value provides a screening for potential weight-related health issues by evaluating your weight in direct proportion to your height. While it is not a diagnostic tool on its own, it offers a reliable starting point for understanding your current physical condition and whether your weight falls within a range that is statistically associated with the lowest risk for chronic diseases such as heart disease, diabetes, and hypertension.

Weight (kg)

Height (cm)

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How it Works

This calculator uses your height and weight to estimate your body composition. By comparing your result to established health ranges, you can get a general idea of whether your weight is appropriate for your stature. It supports both the Metric system (kilograms and centimeters) and the Imperial system (pounds and inches), making it accessible for everyone worldwide. To use the tool, simply select your preferred unit system, enter your current weight and height, and the calculator will instantly provide your BMI score along with your official health category based on WHO guidelines.

Calculation Formula

BMI = weight (kg) / [height (m)]²

Calculation Examples

To help you understand how BMI varies with height and weight, consider these two examples: 1. **Metric Example**: An individual weighing 75 kg with a height of 180 cm (1.8 meters). Using the formula: 75 / (1.8 * 1.8) = 23.15. This falls comfortably within the 'Normal weight' category. 2. **Imperial Example**: An individual weighing 160 lbs with a height of 5 feet 10 inches (70 inches). The imperial formula is [Weight (lbs) / Height (inches)²] * 703. So: (160 / 4900) * 703 = 22.95. This also represents a 'Normal weight' status.

Why use this tool in your daily life?

Knowing your BMI is the first step in a proactive health strategy. It provides a baseline that you can discuss with your doctor, helping you identify if you need to adjust your diet or activity levels to prevent future health complications.