Calculate your Body Mass Index instantly with metric or imperial units. See your category and healthy weight range.
Based on a BMI of 18.5–24.9 (WHO normal range)
Personalized nutrition and fitness plans built around your goals.
May indicate nutritional deficiency or other health issues. Consult a doctor.
Generally considered healthy. Lowest risk of weight-related health issues.
Increased risk of cardiovascular disease, diabetes, and other conditions.
Significantly increased health risks. Consider consulting a healthcare provider.
BMI categories are based on World Health Organization (WHO) classifications. They apply to adults aged 18+ and may not be accurate for athletes, pregnant women, or those with high muscle mass.
Body Mass Index (BMI) is a measure of body fat based on height and weight. It's a simple, inexpensive screening tool used by healthcare professionals worldwide. It does not directly measure body fat but correlates with more direct measures.
According to the World Health Organization: Underweight is BMI below 18.5, Normal weight is 18.5–24.9, Overweight is 25–29.9, and Obese is 30 or higher. These categories apply to adults aged 18 and older.
BMI is a useful screening tool but not a diagnostic tool. It doesn't distinguish muscle from fat, so athletes with high muscle mass may show high BMI despite being healthy. It also doesn't account for body composition, fat distribution, or factors like age, sex, and ethnicity. Combine BMI with other measures like waist circumference for a fuller picture.
Metric: BMI = weight (kg) / [height (m)]². Imperial: BMI = [weight (lbs) / height (in)²] × 703. Example (metric): 70 kg, 1.75 m → 70 / (1.75 × 1.75) = 22.86. Example (imperial): 155 lbs, 5'9" (69 in) → (155 / 69²) × 703 = 22.89.
No, this calculator is for adults aged 18+. Children and teens use BMI-for-age percentile charts that account for growth and development. Consult a pediatrician for child BMI assessment.
BMI is not accurate during pregnancy due to natural weight changes from the baby, placenta, and increased fluid. Pre-pregnancy BMI is used by doctors to determine recommended weight gain during pregnancy.