Is BMI different for women?
The math is not. BMI is your weight in kilograms divided by your height in meters, squared. The CDC uses the same categories for women and men. This page just starts with a sample woman, 5 ft 5 in (165 cm) and 145 lb (66 kg). Her BMI is 24.1, in the healthy range.
What BMI doesn't show is how your body is built. The American Council on Exercise lists 25% to 31% body fat as average for women, and 18% to 24% for men. So a woman and a man with the same BMI often carry very different amounts of fat.
BMI for women by age
Adult BMI cut-offs stay the same from age 20 on. There is no separate chart for women in their 40s, 50s, or 60s.
Age does change what the number means, though. A 2014 review of adults 65 and older found that a BMI in the overweight range was not linked to a higher risk of death. The risk went up for BMIs under 23. For older women, keeping muscle and strength often matters more than a lower number.
Measures that add to BMI
- Waist size. The WHO links a waist over 80 cm (31.5 in) in women with increased health risk, and over 88 cm (34.6 in) with substantially increased risk.
- Waist-to-hip ratio. For women, a ratio of 0.85 or higher is linked with substantially increased risk. Try our waist-to-hip ratio calculator.
- Body fat. Our body fat calculator for women uses a tape measure.
BMI isn't used during pregnancy. The NHS also notes that women from some ethnic groups, including Asian, Black African, and African-Caribbean backgrounds, face more health risks at a lower BMI.
For more on BMI, go back to the main BMI calculator. Talk to your doctor about what a healthy weight looks like for you.