What Is a Healthy BMI? The WHO Range for Women and Men

The WHO BMI Categories

Body Mass Index (BMI) is a simple number that relates your weight to your height. The World Health Organization (WHO) uses it as a population-level screening tool, and its category thresholds are the international standard for adults. Here is the full adult chart:

• Underweight: BMI below 18.5
• Normal (healthy) range: BMI 18.5 to 24.9
• Overweight: BMI 25 to 29.9
• Obese: BMI 30 and above

These bands describe statistical ranges associated with different average health risks across large groups of people. They do not tell you whether any single person is healthy or unhealthy — that depends on many factors a single number cannot capture. If your BMI sits outside the healthy range, treat it as a prompt for a conversation, not a verdict. The app shows your category on a colored scale so you can see at a glance where you fall, with no judgment attached.

Is BMI Different for Women and Men?

This is one of the most searched questions about BMI, and the honest answer is reassuring in its simplicity: the adult BMI scale is the same for women and men. The healthy range is 18.5 to 24.9 regardless of sex, and the same thresholds define underweight, overweight and obesity for everyone. There is no separate "BMI for women" chart or "BMI for men" chart at the adult level.

The calculation itself uses only your weight and height — it does not include sex at all. On average, women carry a higher percentage of body fat than men at the same BMI, and men carry more muscle, but the WHO category boundaries were set as a single adult standard rather than being split by sex. So if you searched for a women's or men's BMI calculator expecting a different formula, you can relax: the number and the categories are identical. Where sex does matter is in body fat percentage and in BMR/TDEE calorie needs, which the app calculates with separate male and female formulas.

Children and teenagers are the exception. For anyone under 18, BMI is interpreted using age-and-sex-specific percentile charts rather than the fixed adult numbers above, because a growing body changes rapidly. This app's categories are intended for adults.

Where BMI Falls Short: Its Limitations

BMI is popular because it is quick and needs only two measurements, but it has real limitations that are important to state honestly. Because it uses only weight and height, BMI cannot tell muscle from fat. A very muscular athlete can have a BMI in the overweight or even obese range while carrying little fat, and an older adult who has lost muscle can have a "normal" BMI while carrying more fat than the number suggests.

BMI is also less meaningful for several groups: highly trained athletes and bodybuilders, older adults (whose muscle mass and height can decline), pregnant and breastfeeding people (whose weight naturally rises), and children and teenagers (who need the percentile charts mentioned above). It also does not reflect where fat is stored — waist measurement or waist-to-height ratio adds useful context that BMI alone misses.

One more nuance: research from a WHO expert consultation suggests that for people of Asian descent, health risks can rise at lower BMI values, so some guidance uses lower cutoffs (around 23 for overweight and 27.5 for obesity). Treat BMI as one screening signal among several, not the whole picture.

This guide is for general information only and is not medical advice — talk to a doctor or qualified health professional about your individual results and any weight or health decisions.