What is calculated?
BMI is weight in kilograms divided by height in metres squared. For 70 kg and 1.70 m, it is approximately 24.2. The category uses the unrounded value; a rounded display can sit close to a boundary.
Why the reference matters
The 2009 Indian consensus used overweight from BMI 23 and obesity from 25. The international card uses 25 and 30. These are named reference systems, not a claim that one threshold is the current rule for everyone.
Current NICE guidance uses lower thresholds for several ethnic backgrounds, including South Asian: overweight from 23 and obesity from 27.5. A clinician can select the appropriate assessment alongside other health information.
Use the result as a screening reference
BMI does not separate muscle from fat or measure where fat is stored. Health assessment may also consider waist measurements, history and other findings. The displayed weight band is calculated from BMI 18.5–22.9 for comparison; it is not a recommended target. Adult categories should not be used for children or during pregnancy.
Frequently asked questions
›Does a BMI category diagnose my health?
No. It is one screening measure. Individual health cannot be determined from BMI alone.
›Why do the two cards differ?
They use different, explicitly named cut-offs. Other guidelines also differ; use the reference appropriate to your clinical assessment.
›Why does a rounded BMI look close to the next category?
The category is calculated before rounding. The displayed BMI is rounded to one decimal place.