What the numbers mean
BMI is your weight in kilograms divided by your height in metres squared. For adults, the World Health Organization uses these ranges: under 18.5 is underweight, 18.5 to 24.9 is a healthy weight, 25 to 29.9 is overweight and 30 or more is obesity.
The healthy weight range shown is the weight that would put someone of your height between a BMI of 18.5 and 24.9.
The limits of BMI
BMI is a quick screening number, not a diagnosis. It does not tell muscle from fat, so athletes can score as overweight while being very fit. It also does not show where fat is stored, which matters for health. Some health services use lower cut-offs for people of South Asian, Chinese and other Asian backgrounds, and children and teenagers are assessed with age-specific charts instead.
If your result worries you, talk to a doctor, who can look at waist size, blood pressure and other measures too.