In older age, muscle mass and general condition matter when interpreting BMI. Winter et al. (2014) describe limitations of the usual BMI interpretation in older adults. Winter et al., 2014. BMI by age
Adult reference ranges
Below the reference rangeunder 18.5Current range
Within the reference range18.5 to 24.9Current range
Above the reference range25 to 29.9Current range
Well above the reference range30 or moreCurrent range
This calculator gives general reference values and does not replace advice from a doctor. For children and teens under 18, during pregnancy and breastfeeding, for very muscular builds and in older age, the results are of limited use.
How the range is calculated
Weight = BMI × height (m)². WHO gives 18.5 to 24.9 as the reference range. This calculator rounds BMI to one decimal before classifying it. It finds whole weights whose displayed BMI falls within the range. At 170 cm this is 54 to 72 kg. The adjacent weights, 53 and 73 kg, fall outside. These are arithmetic boundaries, not a personal recommendation.
Why a range and not one number
Bodies differ in frame, muscle and how fat is distributed. A range is therefore fairer than a single number. Being near the edge of the range does not say much on its own. Discuss personal targets with your doctor.
This calculator gives general reference values and does not replace advice from a doctor. For children and teens under 18, during pregnancy and breastfeeding, for very muscular builds and in older age, the results are of limited use.