BMI Calculator for Women

This calculator accepts age, height and weight. It computes BMI = weight in kilograms ÷ height in meters². Imperial inputs use 2.54 cm per inch and the existing approximate 0.453592 kg per pound before the calculation.

CDC adult BMI calculator (26 June 2024) is intended for adults aged 20 and older. This form follows that age scope. Adult screening thresholds are the same for women and men; the calculator does not use separate sex-specific BMI categories.
References and method last checked: 2026-09-30. Source publication or update dates are shown separately.

Categories use the unrounded BMI: below 18.5, underweight; 18.5 to below 25, healthy weight; 25 to below 30, overweight; and obesity classes I, II and III at 30, 35 and 40. The displayed BMI is rounded separately, so 24.96 can display as 25.0 while remaining below 25.

BMI describes weight relative to height. It does not directly measure fat, muscle or health and is a screening measure rather than a diagnosis.

The body-fat output is a separate prediction from Deurenberg et al. (1991), not part of the BMI category and not a direct measurement. The original study included 1,229 subjects aged 7–83, with BMI 13.9–40.9; it reported an adult prediction error of about 4.1 percentage points and some overestimation in obese subjects.

Predicted body fat (%) = 1.20 × BMI + 0.23 × age − 5.4. The adult paper’s sex coefficient is 0 for females and 1 for males in the combined equation. This route uses the female coefficient.

The result does not provide body-fat health categories or an age-adjusted diagnosis. Values below 0%, above 100%, or non-finite values are shown as unavailable rather than clamped to a physical limit. Inputs outside the study’s observed range are extrapolations and should not be treated as validated individual estimates.

A waist-to-hip ratio divides waist circumference by hip circumference in the same unit. This calculator does not accept either measurement and does not return that ratio.

WHO waist and hip report (2011; consultation in 2008) describes waist measurement midway between the lower rib and hip crest and hip measurement around the widest part of the buttocks. Its discussion includes measurement, population differences and clinical interpretation; a BMI value alone cannot supply this information.

The age input gates the adult BMI result at 20 years and enters the separate body-fat prediction. It does not change the adult BMI thresholds, assess puberty or menopause, or identify a personal target weight.

Pregnancy, older age, muscle mass and clinical history can change the context in which BMI is assessed. CDC pregnancy guidance (15 May 2024) uses prepregnancy BMI; this form is not a pregnancy weight-gain assessment. It does not apply an alternative older-adult “ideal” BMI band.

The reference weight band is derived from the existing BMI endpoints 18.5 and 24.9, not a Hamwi or body-frame formula.

Lower reference weight (kg) = 18.5 × height (m)²; upper reference weight (kg) = 24.9 × height (m)². Imperial results convert these masses to pounds. At 1.65 m, the unrounded reference is approximately 50.4–67.8 kg; displayed precision depends on the calculator’s existing rounding.

This arithmetic describes weights corresponding to a screening band. The 24.9 reference endpoint is a display convention; the healthy-weight category extends to below 25. It is not a personal goal or a recommendation to gain or lose the difference.

• BMI does not distinguish fat, muscle and bone mass or show fat distribution.
• It does not adjust its screening category for athletic build, ethnicity, pregnancy or age beyond the adult eligibility gate.
• A BMI-derived body-fat prediction has model error and cannot replace a measurement.
• The reference weight band cannot determine an individual nutrition or exercise plan.

Consider these results with other clinical information when seeking an assessment. The same adult BMI thresholds on this route do not imply that every person at the same BMI has the same body composition or health risk.