BMI Calculator
Calculate your Body Mass Index (BMI) and assess your weight status.
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About BMI
Body Mass Index (BMI) is a numerical value derived from an individual's weight and height. It provides a simple way to classify weight status into categories that may indicate potential health risks.
The standard formula for BMI is:
BMI = weight (kg) / height² (m²)
For those using imperial units:
BMI = 703 × weight (lbs) / height² (inches²)
BMI values are generally categorized as follows:
Note: Asian populations may have different thresholds, with overweight starting at BMI 23 and obesity at BMI 27.5.
While BMI is a useful screening tool, it has several limitations:
- Muscle mass: BMI doesn't distinguish between muscle and fat. Athletes with high muscle mass may have a high BMI but low body fat.
- Body composition: BMI doesn't account for differences in body composition between individuals.
- Age and gender: BMI interpretation doesn't account for natural variations in body composition related to age and gender.
- Ethnicity: Different ethnic groups may have different relationships between BMI and health risks.
- Fat distribution: BMI doesn't indicate where fat is stored in the body. Abdominal fat (around the waist) poses more health risks than fat in other areas.
For a complete health assessment, BMI should be considered alongside other factors such as waist circumference, blood pressure, cholesterol levels, and family medical history.
Several alternative measurements can provide additional insights:
Waist Circumference
Measures abdominal fat, which is a risk factor for obesity-related conditions. High-risk measurements:
- Men: Greater than 102 cm (40 inches)
- Women: Greater than 88 cm (35 inches)
Waist-to-Hip Ratio (WHR)
Divides waist circumference by hip circumference. High-risk ratios:
- Men: 0.90 or higher
- Women: 0.85 or higher
Waist-to-Height Ratio
Divides waist circumference by height. A ratio of 0.5 or less is considered healthy.
Body Fat Percentage
Measures the percentage of your body that consists of fat. Healthy ranges vary by age and gender.
For the most accurate health assessment, consider using multiple measurement methods in consultation with healthcare professionals.