BMI Calculator

Calculate your BMI and see your healthy weight range instantly. Uses CDC standard adult BMI categories — underweight, normal, overweight, and obese — for both metric and imperial units.

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Body Mass Index Calculator

For adults — metric or imperial units

cm
kg
yrs
Your BMI
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Underweight<18.5Normal18.5-24.9Overweight25-29.9Obese≥30
Healthy Weight Range
Weight to Lose/Gain
BMI Prime
Ideal Body Weight

BMI Chart for Adults — CDC Standards and US Obesity Rates

The CDC classifies adult BMI into four categories: Underweight (below 18.5), Normal weight (18.5–24.9), Overweight (25.0–29.9), and Obese (30.0 and above). According to the most recent CDC data, over 41% of American adults are classified as obese — up from 30% in 2000. Another 31% fall in the overweight category. That means fewer than 30% of US adults have a BMI in the healthy normal weight range, making this the most widely used initial health screening tool in primary care offices across the country.

BMI is a useful starting point, but it has well-known limitations. It doesn't distinguish between muscle mass and fat mass — a muscular 200-pound athlete and a sedentary 200-pound person of the same height get the same BMI despite very different health profiles. The CDC and American Heart Association recommend using BMI alongside waist circumference, body fat percentage (via DEXA or Navy method), and other clinical markers for a complete picture. A waist circumference above 40 inches for men or 35 inches for women indicates elevated health risk even at a normal BMI.

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US Obesity Statistics

CDC data: 41.9% of US adults are obese, with severe obesity (BMI 40+) affecting 9.2%. Southern states like Mississippi and West Virginia consistently show higher obesity rates than Western states. Annual obesity-related healthcare costs exceed $170 billion.

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Healthy Weight Range

For a 5'7" adult, the healthy BMI range of 18.5–24.9 corresponds to roughly 118–159 lbs. Your specific healthy weight range appears in the results above — it's based on your entered height using the standard NIH BMI formula.

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BMI Limitations

BMI doesn't account for muscle mass, bone density, or fat distribution. Athletes often show "overweight" BMI despite excellent health. Elderly adults can show "normal" BMI while carrying excess fat mass due to muscle loss (sarcopenia).

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Beyond BMI

Pair your BMI result with waist-to-height ratio (aim for under 0.5) and body fat percentage for a fuller picture. The American Heart Association considers waist circumference an independent risk marker for cardiovascular disease.

Frequently Asked Questions

CDC BMI categories for US adults: Underweight = below 18.5. Normal/Healthy weight = 18.5--24.9. Overweight = 25.0--29.9. Obese Class 1 = 30.0--34.9. Obese Class 2 = 35.0--39.9. Severe/Morbid Obesity = 40.0+. Approximately 41.9% of US adults are classified as obese per CDC data (2021--2023).
BMI has documented limitations recognized by the CDC and WHO. It does not distinguish muscle from fat (athletes may show "obese" BMI with low body fat). It does not account for fat distribution (abdominal fat is more dangerous than fat elsewhere). Asian Americans face higher metabolic risk at BMI 23 vs the standard 25 threshold used for other groups.
Lower BMI through sustained caloric deficit and physical activity. A 500-calorie daily deficit produces ~1 lb/week of fat loss. CDC recommends 150--300 minutes of moderate aerobic activity weekly plus 2 days of strength training. Even a 5%--10% reduction in body weight significantly improves blood pressure, blood sugar, and cholesterol — measurable health gains before reaching a "normal" BMI.

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