Calculate your Body Mass Index (BMI) instantly. Find your weight category and healthy weight range for your height.
22.9
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BMI Calculator
Body Mass Index (BMI) is a widely used screening tool calculated using the formula:{' '} BMI = weight (kg) / height² (m). Despite its simplicity, BMI remains the standard metric used by the WHO and most health organisations to classify body weight at the population level.
The WHO defines these categories for adults: below 18.5 — underweight, 18.5–24.9 — normal weight, 25.0–29.9 — overweight, 30.0–34.9 — obesity class I, 35.0–39.9 — class II, 40+ — class III (severe).
Limitations
BMI is a useful screening tool but does not directly measure body fat. Athletes with high muscle mass may fall into the "overweight" category despite having low body fat. Conversely, individuals with a normal BMI can still carry excess visceral fat, particularly with a sedentary lifestyle.
For a more accurate assessment: waist circumference (risk threshold: 80 cm for women, 94 cm for men), waist-to-hip ratio, and body fat percentage via bioelectrical impedance analysis or DEXA scan.
Healthy Weight
Maintaining a BMI in the 18.5–24.9 range is associated with lower risk of hypertension, type 2 diabetes, cardiovascular disease, and certain cancers. At BMI above 30, the risk of these conditions rises substantially.
The WHO recommends at least 150–300 minutes of moderate-intensity aerobic activity per week for adults. If your BMI is above 30 or you have existing health conditions, consult a doctor before starting any weight-loss programme.
Key Facts
Below 18.5 — Underweight
May indicate malnutrition or underlying illness. Consult a doctor.
18.5–24.9 — Normal weight
The optimal range for most adults, associated with the lowest health risk.
25.0–29.9 — Overweight
Moderately elevated risk. Small lifestyle changes can have a significant impact.
30+ — Obese
Significantly elevated chronic disease risk. Medical consultation recommended.
BMI in children
For those under 18, BMI is interpreted using age- and sex-specific percentile charts.
Waist circumference
Risk threshold: 80 cm for women, 94 cm for men — regardless of BMI.
A BMI between 18.5 and 24.9 is considered normal weight. Below 18.5 is underweight, 25-29.9 is overweight, and 30 or above is obese.
BMI = weight (kg) / height² (m). For example, a person weighing 70 kg at 1.75 m has a BMI of 70 / (1.75 × 1.75) = 22.9.
BMI is a useful screening tool but has limitations. It may overestimate body fat in athletes and underestimate it in older adults. Consult a healthcare provider for a complete assessment.
A BMI of 25.0 to 29.9 is classified as overweight. A BMI of 30.0 or higher is classified as obese.
Achieving a healthy BMI typically involves a balanced diet and regular physical activity. Even modest weight loss of 5-10% can significantly improve health outcomes.