BMI is your weight in kilograms divided by your height in meters squared: BMI = kg / m2. For example, 70 kg at 1.75 m is 70 / (1.75 x 1.75) = 70 / 3.0625, which is about 22.9. BMI is a screening number, not a diagnosis, and a free BMI calculator computes it instantly in metric or imperial units.
Metric: BMI = weight in kg divided by height in meters squared. Imperial: BMI = 703 x weight in pounds divided by height in inches squared. So 154 pounds at 5 feet 9 inches (69 inches) is 703 x 154 / (69 x 69), which is about 22.7. A calculator saves you the squaring and lets you switch units without converting by hand.
The standard adult ranges are: under 18.5 underweight, 18.5 to 24.9 normal weight, 25 to 29.9 overweight, and 30 or above obese. But BMI only relates weight to height; it cannot see body composition. Muscular people can score as overweight while carrying little fat, and the ranges apply to adults, not children. Treat it as a quick screening signal to discuss with a professional, not a verdict.
Under 18.5 is underweight, 18.5 to 24.9 is normal weight, 25 to 29.9 is overweight, and 30 or above is obese, for adults.
Often not. BMI cannot distinguish muscle from fat, so muscular athletes can read as overweight. It is a screening metric, not a body composition measure.
80 / (1.80 x 1.80) = 80 / 3.24, which is about 24.7, at the top of the normal range.