BMI Calculator

BMI is calculated using one of these formulas:

• Metric: BMI = Weight (kg) ÷ [Height (m)]²
• Imperial: BMI = [Weight (lbs) ÷ (Height (in))²] × 703

The resulting number indicates which category your weight falls into: underweight (below 18.5), healthy weight (18.5-24.9), overweight (25-29.9), or obesity (30 and above).

BMI categories are generally interpreted as follows:

• Below 18.5 (Underweight): May indicate nutritional deficiencies, hormonal imbalances, or other health issues.
• 18.5-24.9 (Healthy Weight): Generally associated with lower risk of weight-related health problems.
• 25-29.9 (Overweight): May increase risk for health problems including high blood pressure, heart disease, and type 2 diabetes.
• 30 and above (Obese): Higher risk for heart disease, stroke, type 2 diabetes, and certain cancers.

These categories are the same for men and women of all body types and ages. However, they may not be accurate for all individuals.

Despite its widespread use, BMI has several important limitations:

• Doesn't distinguish between muscle and fat: Athletes with high muscle mass may be classified as “overweight” or “obese” despite having low body fat.
• Doesn't account for body composition: Two people with the same BMI may have very different body compositions and health risks.
• Doesn't consider age and sex: Older adults often have more body fat than younger adults with the same BMI, and women typically have more body fat than men with the same BMI.
• May not be accurate for certain ethnicities: Different ethnic groups may have different associations between BMI and health risks.
• Doesn't measure fat distribution: Abdominal fat (visceral fat) carries more health risks than fat stored in other areas, but BMI doesn't indicate where fat is stored.

If your BMI falls outside the "healthy" range, consider these actions:

• Underweight: Consult a healthcare provider to rule out underlying conditions. Focus on nutrient-dense foods and possibly add strength training to build muscle mass.
• Overweight or Obese: Start with small, sustainable changes like increasing physical activity and focusing on a balanced diet rich in fruits, vegetables, lean proteins, and whole grains.
• Any BMI category: Regular physical activity (aim for 150 minutes of moderate activity per week) benefits everyone regardless of weight.
• Consider other measurements: Waist circumference, waist-to-hip ratio, body fat percentage, and overall fitness level can provide additional health insights.

Remember that BMI is just one factor in assessing health. Blood pressure, cholesterol levels, blood sugar, family history, and lifestyle all play important roles in your overall health picture.

For a more complete health assessment, consider these additional measures:

• Waist circumference: Men with waists over 40 inches (102 cm) and women with waists over 35 inches (88 cm) have higher health risks, regardless of BMI.
• Waist-to-hip ratio: Dividing waist measurement by hip measurement can indicate fat distribution. Ratios above 0.9 for men and 0.85 for women suggest increased health risks.
• Body fat percentage: Measured by skinfold tests, bioelectrical impedance, or other methods, this provides a more direct measure of body composition.
• Fitness level: Cardiovascular fitness, strength, and flexibility are important indicators of health independent of weight.
• Metabolic health markers: Blood pressure, cholesterol levels, blood glucose, and other lab values provide important information about your health.