BMI is weight in kilograms divided by height in metres squared. A 70 kg adult who is 175 cm tall has a BMI of 22.9, inside the 18.5 to 24.9 range.
The formula
BMI = weight (kg) ÷ height (m)². For 70 kg and 1.75 m that is 70 ÷ 3.0625 = 22.9.
For adults the standard WHO bands are: under 18.5 underweight, 18.5 to 24.9 normal, 25 to 29.9 overweight, 30 and above obesity.
Healthy weight by height
Inverting the formula gives the weight range that lands in the 18.5 to 24.9 band. At 175 cm it runs from 56.7 kg to 76.6 kg. The table gives the range for other heights.
What BMI does not tell you
BMI cannot tell fat from muscle, ignores where fat is carried and was built for adults, not children, whose ranges depend on age and sex. Use it as a screening number, and talk to a health professional about what it means for you.
| Height (cm) | From (kg) | To (kg) |
|---|---|---|
| 160 | 47.4 | 64.0 |
| 170 | 53.5 | 72.3 |
| 180 | 59.9 | 81.0 |
| 190 | 66.8 | 90.3 |
FAQ
What is a normal BMI?+
For adults, 18.5 to 24.9 under the WHO classification.
Is BMI accurate for athletes?+
Often not. Muscle weighs more than fat, so a muscular person can read as overweight at a healthy body fat level.