Maternity Bra and Nursing Bra Sizing Chart

The right fit is essential in a comfortable maternity or nursing bra

Maternity and nursing bras aren’t always a pregnancy essential – but for many women, the specialty cut of a maternity bra adds extra support and comfort. Your ribcage expands to accommodate your growing baby, and the beginning of the milk production process will increase your breast size – for some women, substantially increase breast size. As with any pregnancy ‘symptom’, the increase of a mom’s bra size varies from woman to woman (I actually know some women whose bra cup size decreased when they were nursing). In general, you can expect that your bra size will increase by at least one band and one cup size (for instance, if you are a 36C when you get pregnant, you will probably be at least a 38D when you have your baby).

Before investing in maternity or nursing bras, you should take accurate measurements. Since you may buy bras at different times during your pregnancy (and when nursing), it’s a good idea to take new measurements any time you’re ready to purchase another bra.

Bra Band Size

Do not measure under the bustline as you would a pre-pregnancy bra. Your ribcage has expanded to make room for baby to a point where measuring here does not ensure an accurate fit. Instead, measure around the chest, just under the arms and above the bust. This measurement is your band size. If your measurement ends in a fraction or is an odd number, round up to the next even size. For instance, if you measure 36 ½, 37 or 38, you would be a 38.

Cup size

Measure around the fullest point of the bust (measurement A), keeping the tape measure level without pulling tight. Measure under the bust line (measurement B). Refer to the chart below - the difference between measurements A and B is your cup size (1 inch = 1 cup size).


Cup Size















Additional Information and Articles:

Maternity and Nursing Bras

Guide to Maternity Bras and Nursing Bras