Body Mass Index from your height and weight, in metric or imperial.
BMI = weight in kilograms ÷ (height in metres)². The standard adult ranges: under 18.5 underweight, 18.5–24.9 healthy, 25–29.9 overweight, 30 and above obese. BMI is a population screening tool, not a body-fat measurement — it overestimates fat in very muscular people and underestimates it in older adults, which is worth knowing before treating the number as a verdict.
Is BMI accurate for athletes? Not really — muscle weighs more than fat, so a lean athlete can score "overweight". Waist circumference and body composition tests tell the fuller story.
What BMI should I aim for? The healthy band is 18.5–24.9 for most adults. Anything about your own target is a conversation for a clinician who knows your history.