Research on female body attractiveness, crucial to aesthetics, art, and health, examines features determining beauty and why they are appealing. Evolutionary theories link attractiveness to health and fertility, with the waist-to-hip ratio (WHR) as key indicator. However, using WHR as attractiveness measure is challenging, as it is based on three-dimensional (3D) information (body circumference), which is typically not readily available to the observer. To address this issue, studies on body attractiveness that commonly present two-dimensional (2D) stimuli (such as line drawings, photographs, or historical paintings) have simply used 2D versions of the WHR. However, these measures are viewpoint dependent, and it remains unclear how they relate to their 3D counterpart. In order to fill this gap, we investigated the relationship between 3D WHR and its 2D measures while also considering the influence of the body mass index (BMI). From photographs of 153 women with known 3D WHR and BMI, we digitally extracted the 2D WHR in frontal and profile view. Both 2D measures correlate positively with the corresponding 3D WHR, but the frontal 2D WHR underestimates and the profile 2D WHR overestimates the 3D WHR. Regression analysis shows that adding the BMI to a simple model with frontal 2D WHR significantly increases its predictive power up to R² = .527. However, it does not significantly increase by adding the 2D profile WHR. These results underscore the limitations that need to be taken into account when using different 2D body measurements for predicting body attractiveness.