BMI Calculator for Women
Result
BMI
- Healthy weight, low end
- 50.4 kg
- Healthy weight, high end
- 68.1 kg
- Obesity line weight
- 81.7 kg
A BMI calculator for women has an honest answer that most pages avoid: the thresholds are the same for both sexes. BMI is weight in kilograms divided by height in metres squared, and the bands — 18.5, 25 and 30 — are not read differently for women. What does differ is the arithmetic you have to do: this page converts each threshold into the number of kilograms it corresponds to at your height, so you can weigh yourself and compare directly instead of looking your BMI up in a table. It also tells you the weight at which the obese band begins.
Healthy and obese weight lines for women, by height
| Height (cm) | Healthy from (kg) | Healthy to (kg) | Obese from (kg) |
|---|---|---|---|
| 150 | 41.6 | 56.3 | 67.5 |
| 155 | 44.4 | 60.1 | 72.1 |
| 160 | 47.4 | 64 | 76.8 |
| 165 | 50.4 | 68.1 | 81.7 |
| 170 | 53.5 | 72.2 | 86.7 |
| 175 | 56.7 | 76.6 | 91.9 |
| 180 | 59.9 | 81 | 97.2 |
Each column is one BMI threshold multiplied by height squared: 18.5, 25 and 30. The same table applies to men — only the body composition behind the number differs.
Formula
BMI = weight (kg) ÷ height (m)², and weight at a threshold = threshold × height (m)²
- height
- Standing height, in metres (m)
- weight
- Body weight, in kilograms (kg)
Use it when you want a weight to aim at or a weight to stay under, rather than a BMI value to look up. The three lines it prints — the bottom of the healthy range, the top of it, and the start of the obese band — are the same cut-offs your doctor's chart uses, only written in kilograms for your height. If you are pregnant, this is not the page for you; weight gain in pregnancy is judged against a different table indexed by your pre-pregnancy BMI.
Worked examples
165 cm, 60 kg
- Height squared: 1.65 × 1.65 = 2.7225
- 60 ÷ 2.7225 = 22.0, so the BMI is 22.0
- Healthy range: 18.5 × 2.7225 = 50.4 kg up to 25 × 2.7225 = 68.1 kg
- Obese band starts at 30 × 2.7225 = 81.7 kg
At 22.0 you sit in the lower half of the healthy range, with 8.1 kg of headroom before you cross the 25 line.
175 cm, 75 kg
- Height squared: 1.75 × 1.75 = 3.0625
- 75 ÷ 3.0625 = 24.5
- Healthy range: 56.7 kg to 76.6 kg
- Obese band starts at 91.9 kg
24.5 is inside the healthy range but only 1.6 kg below the line. The same top line sits 8.5 kg lower at 165 cm, because height is squared in every one of them.
Limitations
BMI is not read differently for women, so this page cannot give you a female-specific threshold — no health body publishes one. It is also blind to body composition: at the same BMI a woman with more muscle and less fat reads identically to one with the reverse, and after menopause the same BMI usually corresponds to a higher fat percentage. BMI was not validated in pregnancy or below the age of 20. Waist circumference is the measure that catches where fat sits, and it is a separate judgement, not one this page can make.
Frequently asked questions
- Is BMI different for women?
- No. The cut-offs — 18.5, 25 and 30 — apply to both sexes, and no health body publishes a separate female BMI chart. What differs between the sexes is body composition at a given BMI: women typically carry a higher fat percentage than men at the same value, which is why BMI can understate fat in women rather than why the thresholds change.
- What is BMI 25 in kg?
- It depends on your height, because the threshold has to be multiplied by height squared. At 165 cm, BMI 25 corresponds to 68.1 kg; at 175 cm it is 76.6 kg. That is what this calculator prints in the second line of its results — the weight at which the healthy range ends for your height.
- What is BMI 30 in kg?
- The same multiplication with 30 instead of 25: 81.7 kg at 165 cm and 91.9 kg at 175 cm. Above that weight the obese band begins. Because height is squared, the gap between the 25 line and the 30 line grows quickly with height — 13.6 kg at 165 cm, 15.3 kg at 175 cm.
- Should I use this if I am pregnant?
- No. Weight gain in pregnancy is judged against a table indexed by pre-pregnancy BMI, not against a fixed band, and the whole point of that table is that gaining weight is expected. This site has a separate pregnancy weight gain calculator for it. Entering a pregnancy weight here will tell you that you are above the healthy range, which is not a useful thing to know.
- Why does this page not show BMI Prime?
- Because it would need explaining. BMI Prime is your BMI divided by 25, a device for comparing yourself to the top of the healthy range — and the range can be written in kilograms directly, which is what this page does instead. One number in the units of your own bathroom scale is easier to act on than two.
- Does the healthy weight for women differ from the men's?
- Not by sex. At any given height the healthy weight range is the same for women and men, because BMI is defined on height and weight alone. Two people of the same height share the same three lines. Where they differ is in body composition: at the same BMI, a woman usually carries more fat and less muscle than a man.
References
- Obesity: preventing and managing the global epidemic (WHO Technical Report Series 894) — World Health Organization
- Body Mass Index (BMI) — healthy weight — US Centers for Disease Control and Prevention