BMI for women: what the numbers mean
The body mass index uses the same formula and the same adult categories for women and men. The World Health Organization classifies adult BMI as follows:
| BMI | Category |
|---|---|
| Below 18.5 | Underweight |
| 18.5 – 24.9 | Healthy weight |
| 25 – 29.9 | Overweight |
| 30 and above | Obese |
Why a separate BMI calculator for women?
The BMI value does not change with sex, but what it says about your body does. At the same BMI, women typically have about 10 percentage points more body fat than men. That is why this page adds a body fat estimate calibrated for women (Deurenberg formula: body fat % = 1.20 × BMI + 0.23 × age − 10.8 × sex − 5.4, with sex = 0 for women). For example, a 35-year-old woman with a BMI of 22.8 has an estimated body fat of about 30%.
Healthy BMI chart by height (women)
| Height | Healthy weight (BMI 18.5–24.9) |
|---|---|
| 150 cm (4 ft 11 in) | 42 – 56 kg (92 – 124 lb) |
| 155 cm (5 ft 1 in) | 44 – 60 kg (98 – 132 lb) |
| 160 cm (5 ft 3 in) | 47 – 64 kg (104 – 141 lb) |
| 165 cm (5 ft 5 in) | 50 – 68 kg (111 – 149 lb) |
| 170 cm (5 ft 7 in) | 53 – 72 kg (118 – 159 lb) |
| 175 cm (5 ft 9 in) | 57 – 76 kg (125 – 168 lb) |
Limits of BMI for women
- Pregnancy: BMI is not valid during pregnancy; use your pre-pregnancy weight and follow your midwife or doctor.
- Waist size: a waist above 88 cm (35 in) for women signals higher health risk even at a normal BMI.
- Age: older adults lose muscle, so the same BMI can hide more body fat.
Also see the BMI calculator for men, the general BMI calculator, and the calorie and TDEE calculator to plan a weight change.
BMI through life stages
A woman’s body composition changes with age even when her weight stays the same. After menopause, muscle mass tends to fall and fat tends to move towards the abdomen, so the same BMI can mean more body fat at 60 than at 30. That is why the calculator includes your age in the body fat estimate.
Waist-to-height ratio: a useful second check
Divide your waist (measured at the navel) by your height, in the same units. A ratio below 0.5 is generally linked to lower health risk for adults. A woman 165 cm tall with a 78 cm waist has a ratio of 0.47. It is a quick way to catch abdominal fat that BMI alone can miss.
How to measure yourself accurately
- Weigh yourself in the morning, after the bathroom and before eating, in light clothing.
- Weight can vary by 1–2 kg across the menstrual cycle; compare readings taken at the same point in the cycle.
- Measure height without shoes, standing straight against a wall, and track the trend over several weeks.
To turn your result into a plan, estimate your daily needs with the calorie and TDEE calculator and the calories you burn on foot with the walking calorie calculator.