BMI Calculator for Women
Enter your height and weight to get your body mass index (BMI) and the World Health Organization category it falls in. BMI is a quick screening number for adults. It is not a measure of health or of body fat.
Free, no sign-up. What you enter stays in your browser: it is not saved or sent to HerFound. Reviewed .
Units
Enter your height and weight to see your BMI.
This is general information, not medical advice. It cannot take your own health history into account. For anything that worries you, speak to a doctor, midwife or pharmacist.
How it works
BMI is weight in kilograms divided by height in metres squared. For example, 65 kg at 1.65 m is 65 ÷ (1.65 × 1.65) = 23.9. If you enter pounds, feet and inches, the calculator converts them to kilograms and metres first.
The result is shown to one decimal place and matched to the WHO adult categories: under 18.5 is underweight, 18.5 to 24.9 is healthy weight, 25 to 29.9 is overweight, and 30 or more is obesity (class 1 from 30, class 2 from 35, class 3 from 40).
The weight range shown is the range of weights that give a BMI of 18.5 to 24.9 at your height. It is the range WHO classes as healthy weight for this height. It is a description of the category, not a goal.
The formula and the categories are the same for women and men. BMI does not use age or sex.
What it cannot tell you
- BMI cannot tell muscle from fat, and it does not show where fat is carried. A person with a lot of muscle can have a high BMI without having a lot of body fat.
- It is not valid in pregnancy, and it is for adults aged 18 and over only. Children and teenagers need age-specific charts.
- It is less accurate for athletes, for older adults, and for some ethnic groups. Some bodies, such as NICE and the NHS in the UK, use lower thresholds (overweight from 23, obesity from 27.5) for people with a South Asian, Chinese, other Asian, Middle Eastern, Black African or African-Caribbean family background.
- BMI is a screening number, not a diagnosis. If you have questions about your weight or your health, a doctor or nurse can look at the whole picture.
Apps that do this for you
A calculator answers once. These apps keep track over time. Compare all women's fitness apps.
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Common questions
You calculate BMI by dividing your weight in kilograms by your height in metres squared. In US units, multiply your weight in pounds by 703 and divide by your height in inches squared. For example, 65 kg at 1.65 m gives a BMI of 23.9.
No, BMI is calculated the same way for women and men. The formula uses only height and weight, and the WHO adult categories are the same for both. Women usually carry more body fat than men at the same BMI, which is one reason BMI is only a rough guide.
WHO classes a BMI of 18.5 to 24.9 as healthy weight for adults. Under 18.5 is classed as underweight, 25 to 29.9 as overweight and 30 or more as obesity. These bands describe health risk across large groups of people, so they fit some individuals better than others.
BMI is a rough screening tool, not an exact measure. It cannot tell muscle from fat, so it can be misleading for athletes, older adults and people from some ethnic backgrounds. It is not valid during pregnancy.
No, BMI is not valid during pregnancy because your weight includes the baby, the placenta and extra fluid. Maternity services use your BMI from before pregnancy or from your first appointment. Ask your midwife or doctor if you have questions about weight in pregnancy.