BMI Calculator for Women
The same formula everyone uses, and what it misses specifically for women.
Your measurements
Your result
Why the formula does not ask your sex
The first thing worth saying plainly: BMI is calculated identically for women and men. Weight in kilograms divided by height in metres squared, and the WHO adult cut-points — 18.5, 25 and 30 — are the same for both. Any calculator asking your sex is using it for something else on the page or not using it at all.
What differs is what the number conceals. At an identical BMI, women carry substantially more body fat than men — typically 8-10 percentage points more — because essential fat is higher for reproductive function. Healthy body fat ranges run roughly 21-32% for women against 8-19% for men. A woman at BMI 24 and a man at BMI 24 are not in comparable body composition, which is why body fat percentage and waist measurement tell you more than BMI alone.
Two life stages where BMI stops applying. It is not valid during pregnancy — gestational weight gain is assessed against pre-pregnancy BMI using separate Institute of Medicine ranges, not by recalculating as you go. And around menopause, falling oestrogen shifts fat storage from hips and thighs toward the abdomen; BMI can stay completely unchanged while cardiometabolic risk rises, because the distribution moved. Waist-to-height ratio catches that shift where BMI cannot.
Medical disclaimer. This calculator is for general information and education only. It is not medical advice, not a diagnosis, and not a substitute for professional care. BMI is a screening figure rather than a diagnosis, it is not valid during pregnancy, and it cannot assess body composition or fat distribution on its own.Speak to a doctor or another qualified clinician about any health decision.Last reviewed .
Frequently asked questions
Is BMI calculated differently for women?
No. The formula is weight in kilograms divided by height in metres squared, and the WHO adult categories of 18.5, 25 and 30 apply identically to both sexes. Sex affects how to interpret the result, not how to compute it.
What is a healthy BMI for a woman?
The WHO healthy range is 18.5 to 24.9 for all adults. Because women naturally carry more essential body fat than men, a woman at the upper end of that range can have a higher body fat percentage than a man with the same BMI.
Can I use BMI during pregnancy?
No. BMI is not interpreted during pregnancy. Weight gain is assessed against your pre-pregnancy BMI using Institute of Medicine ranges, and your antenatal team sets the target rather than a general formula.
Does BMI change through menopause?
The number often does not, but what it means can. Falling oestrogen shifts fat storage from hips and thighs toward the abdomen, so metabolic risk can rise at an unchanged BMI. Waist-to-height ratio detects that redistribution where BMI cannot.
What is a healthy body fat percentage for women?
Commonly cited ranges are about 21-32%, with athletes often lower. Essential fat for women is around 12%, considerably higher than the roughly 3% for men, and sustained levels near that minimum are associated with hormonal disruption.