Health & Fitness
What Is a Healthy BMI? The Complete BMI Chart for Adults
BMI (Body Mass Index) is the most widely used screening tool for assessing whether a person's weight is in a healthy range relative to their height. Here is what the numbers mean, the standard ranges, and what BMI can and cannot tell you.
BMI categories for adults
Source: World Health Organization (WHO)
How BMI is calculated
BMI = weight (kg) ÷ height (m)². In imperial units: BMI = (weight in lbs ÷ height in inches²) × 703. A person who is 70kg and 1.75m tall has a BMI of 70 ÷ (1.75 × 1.75) = 22.9 — within the healthy range.
The formula is simple and requires only two measurements, which is why it is used universally by healthcare systems for initial screening. It does not require blood tests, imaging, or specialised equipment.
What BMI doesn't tell you
BMI does not distinguish between muscle and fat. A professional athlete with very low body fat might have a BMI in the "overweight" range because muscle is dense. Conversely, someone with a "normal" BMI could have high body fat and poor metabolic health.
BMI also ignores where body fat is stored. Abdominal fat (around the waist) is significantly more health-relevant than fat stored in the legs or arms. Waist circumference is a complementary measure that BMI alone does not capture. Always interpret BMI in context with other health markers, and consult a healthcare professional for individual advice.
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Calculate My BMI →Frequently asked questions
What is considered a healthy BMI?
For adults, a BMI between 18.5 and 24.9 is classified as healthy weight by the World Health Organization. Below 18.5 is underweight. 25–29.9 is overweight. 30 and above is obese. These ranges are the same for both men and women, though BMI does not account for differences in body composition between sexes.
What BMI is considered overweight?
A BMI of 25.0 or higher is classified as overweight. A BMI of 30.0 or higher is classified as obese. Some health authorities further subdivide obesity: Class I (30–34.9), Class II (35–39.9), and Class III or 'morbid obesity' (40 and above). These thresholds are based on population-level studies of health risk.
Is BMI the same for men and women?
The BMI calculation and classification ranges are identical for men and women. However, BMI does not account for differences in body composition — men typically have more muscle mass and less body fat than women at the same BMI. Some health professionals use body fat percentage alongside BMI for a more complete picture.
What is the ideal BMI by age?
For adults aged 20 and over, the standard BMI classification applies regardless of age: 18.5–24.9 is healthy. For children and teenagers (under 20), BMI is age- and sex-specific and interpreted using growth charts — a child's BMI percentile relative to peers of the same age and sex is what matters, not the adult ranges.
Can you be healthy with a high BMI?
Yes — BMI is a screening tool, not a diagnostic one. Athletes and muscular individuals often have high BMIs because muscle is denser than fat, yet they have low body fat percentages and excellent health markers. A high BMI person with good blood pressure, cholesterol, and blood sugar may be healthier than a normal BMI person with poor metabolic health.
How accurate is BMI as a health measure?
BMI is a useful population-level tool but has known limitations for individuals. It does not measure body fat directly, does not distinguish between muscle and fat, does not account for where body fat is distributed (waist fat is more health-relevant than leg fat), and applies adult ranges to a diverse global population. Healthcare providers use BMI alongside other measures for individual assessment.