BMI Calculator
Work out your Body Mass Index (BMI) from height and weight using metric (kg, cm) or US/UK imperial (lb, ft and in). Results are general estimates for informational purposes only—they are not medical advice and do not replace consultation with a doctor or registered dietitian.
Choose metric (kg, cm) or imperial (lb, ft/in)
Enter kg if metric, or lb if imperial
Used when unit system is metric
Used when unit system is imperial
Extra inches; used with feet for imperial
Work out your Body Mass Index (BMI) from height and weight using metric (kg, cm) or US/UK imperial (lb, ft and in). Results are general estimates for informational purposes only—they are not medical advice and do not replace consultation with a doctor or registered dietitian.
Metric: BMI = weight (kg) ÷ height (m)² Imperial: BMI = 703 × weight (lb) ÷ height (in)² WHO adult categories: under 18.5 underweight; 18.5–24.9 normal; 25–29.9 overweight; 30+ obese
Weight 70 kg, height 175 cm Height in metres: 175 ÷ 100 = 1.75 m BMI = 70 ÷ (1.75 × 1.75) = 70 ÷ 3.0625 ≈ 22.9 Category: normal weight range (18.5–24.9)
In metric, divide weight in kilograms by height in metres squared. In imperial, multiply 703 by weight in pounds, then divide by height in inches squared.
WHO adult ranges group BMI into underweight (under 18.5), normal (18.5–24.9), overweight (25–29.9), and obese (30+). They describe population trends, not a diagnosis on their own.
No—pick one system. Enter kg with cm, or lb with ft and in. Mixing units gives a wrong result.
No. BMI is a rough screening tool. It can misclassify muscular athletes, older adults, pregnant people, and some ethnic groups. Treat the number as an estimate and ask a healthcare professional if you need personal advice.
No. This calculator provides general informational estimates only and does not replace consultation with a doctor or registered dietitian.
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