Is BMI calculated differently for women?

No. The BMI formula is the same for all adults: weight in kilograms divided by height in metres squared, and the standard categories of underweight (under 18.5), healthy weight (18.5 to 24.9), overweight (25 to 29.9) and obese (30 and over) also apply to everyone. What differs is the interpretation. Women naturally carry more body fat than men at the same BMI, which is healthy and normal, so a woman and a man with identical BMI scores will usually have quite different body compositions.

What is a healthy body fat percentage for women?

For adult women a healthy body fat percentage typically sits around 21 to 33 percent, noticeably higher than the typical male range, because essential fat requirements are higher for women. This calculator estimates body fat from your BMI and age using the Deurenberg formula for women, which is a population-level estimate rather than a body scan, so treat it as a rough guide and use a DEXA scan or skinfold measurement if you need an accurate figure.

When is BMI misleading for women?

BMI should not be used during pregnancy, because weight gain in pregnancy is expected and healthy. It can also overstate body fat for very muscular women, such as athletes and regular weight trainers, and understate it for older women who have lost muscle mass. BMI also does not show where fat is carried, which matters for health risk, so pair it with a waist measurement or waist-to-hip ratio and talk to your doctor about what a healthy weight looks like for you.

BMI Calculator for Women

This BMI calculator for women works out your Body Mass Index from your height and weight, then adds two things a standard BMI tool leaves out: an estimated body fat percentage based on your age, and the healthy weight range for your exact height. The BMI formula itself is the same for everyone, your weight in kilograms divided by your height in metres squared, but the way you read the number differs for women. Women naturally carry more body fat than men at the same BMI, which is healthy and normal, so this page pairs your BMI with the Deurenberg body fat estimate for women and explains what a typical healthy range looks like, usually about 21 to 33 percent for adult women. Enter your height, weight and age, and the calculator returns your BMI to one decimal place, the category it falls into using the standard adult cut points, your estimated body fat percentage, and the weight band that keeps your BMI between 18.5 and 24.9. Use it to track changes over time or to make sense of a number your GP or midwife has mentioned. BMI is a screening figure only: it does not suit pregnancy, and it can mislead for very muscular or older women, so treat the result as general information rather than medical advice.

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Height

Weight

Age

years

23.9

BMI: healthy weight range

Estimated body fat31.3%

Healthy weight for your height50.4 kg to 67.8 kg

CategoryHealthy

Body fat is estimated from BMI and age using the Deurenberg formula for women; a healthy range for adult women is typically about 21 to 33 percent. The healthy weight band keeps your BMI between 18.5 and 24.9.

General information only, not medical advice. BMI does not apply in pregnancy and can mislead for very muscular or older women. Talk to your doctor about what a healthy weight means for you.

How it works

BMI is your weight in kilograms divided by your height in metres squared. A result under 18.5 counts as underweight, 18.5 to 24.9 as the healthy weight range, 25 to 29.9 as overweight, and 30 or more as obese; these cut points are the same for women and men. The healthy weight band shown is simply the formula run in reverse: 18.5 and 24.9 multiplied by your height in metres squared gives the lightest and heaviest weights that keep you in the healthy range. The body fat estimate uses the Deurenberg equation for women, 1.2 times BMI plus 0.23 times age minus 5.4, which reflects the fact that body fat tends to rise with age at the same BMI. It is a statistical estimate from population data, not a measurement of your own body, so a lean, muscular woman will usually carry less fat than the estimate suggests and the only way to know precisely is a body composition scan.

Worked example

You are 35 years old, 165 cm tall and weigh 65 kg. Your height in metres squared is 1.65 x 1.65, which is 2.7225, and 65 divided by 2.7225 gives a BMI of 23.9, inside the healthy weight range. The Deurenberg estimate is 1.2 x 23.9 plus 0.23 x 35 minus 5.4, which is about 31.3 percent body fat, sitting within the typical healthy band of about 21 to 33 percent for adult women. The healthy weight range for 165 cm runs from 18.5 x 2.7225, which is 50.4 kg, up to 24.9 x 2.7225, which is 67.8 kg, so at 65 kg you sit in the upper half of that band with a little under 3 kg of headroom before BMI would tip into the overweight range.

Related calculators

BMI Calculator: standard BMI with metric and imperial units.
Body Fat Percentage Calculator: body fat from tape measurements.
Ideal Weight Calculator: ideal weight formulas for your height.
Waist to Hip Ratio Calculator: where you carry weight.
TDEE Calculator: daily energy needs.

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