Our body composition plays a significant role in how a bra fits us. The flesh of someone with a high body fat will be softer than someone with low body fat, and will therefore have more give under the tension of a bra band. Someone with a higher body fat will therefore likely require a smaller band that someone with low body ft but the same under bust measurement in order to ensure a tight enough band for sufficient support.
Calculating your band size
An increasingly method of estimating bra size suggests that a woman’s band size is the same as her under bust measurement in inches (e.g. an under bust measurement of 32 inches requires a 32 band). This method is however more reliable for women with smaller under bust measurements, e.g. 26 to 32, and who therefore tend to have low body fat. This is because their under busts are quite reliably firm. The reliability of this method however decreases as the under bust measurement increases due to an increased variation in body composition; some women have large rib cages but little fat, some have lots of muscle and others have lots of fat. Larger under bust measurements therefore vary greatly in how much give their flesh has and therefore how small their band needs to be to offer sufficient support.
Although not prescriptive, we consider bra size calculations as useful tools in finding a starting point only when finding your size, especially amidst the sometimes confusing and overwhelming information available regarding correct bra fit. We do however suggest that when using bra calculators, you factor in the role of body composition. Our bra size estimator takes this into account by offering a wider range of bra sizes to try for larger under bust measurements.
Please be mindful that straps and bands will indent more on women with higher body fat due to having softer flesh. Indentations therefore do not necessarily indicate that the straps or band are too tight; they should be snug enough to offer support but not painful. Please view our bra fitting guide for further fitting guidance.
Breast composition plays a significant role in how a bra fits. Some women have very firm and heavy breasts that tend to maintain a degree of their shape when sitting within a bra. Other women however can have softer breasts that adopt the cup shape when sitting in a bra.
Different breasts tend to be better suited to different bra styles and materials. Women with softer breast tissue for example may require bras that are composed of firmer fabrics and that have significant tension on the underarm to help pull in the breast tissue from the sides and provide more forward projection. Women with firmer breasts may be better suited to balcony or plunge bras than softer breasted women because their breasts are better able to maintain their shape without spilling over the cups or spilling into the sides or middle of the bra.
The same bra can look very different on two women with breasts of the same size but with different composition. It is therefore worth considering your breast composition when bra shopping; to consider which styles will provide the best support and shape. And to also not feel disheartened if a bra looks very different on you than it does on someone else. We are all different and therefore sometimes require different bra styles and fabrics to obtain our desired shape and support.