Nursing Bra Size Calculator
Estimate a current starting size for nursing or postpartum bra shopping from your present measurements. The result is a sizing estimate, not a prediction of future breast changes.
How to measure for a nursing bra
Use your current underbust and bust measurements rather than automatically returning to a pre-pregnancy size. Keep the underbust tape level and comfortably firm, then measure the fullest part of the bust without compressing tissue.
Why nursing fit can be different
Breast fullness can vary during the nursing period, and the most comfortable amount of room depends on the person, the stage of nursing and the bra design. A calculator cannot predict those changes. It can only translate the measurements you enter into a starting size.
Features worth checking in a nursing bra
Nursing access
Choose an opening mechanism that is practical for how you plan to feed and easy to operate when you need it.
Adjustability
Adjustable bands and straps can help accommodate normal changes in fit without relying on a single fixed measurement.
Support and comfort
The band should feel supportive without painful pressure, while the cups should provide appropriate coverage without cutting into tissue.
Room for change
If buying before delivery or early postpartum, remember that today's size is not a guarantee of a later size. Check the garment's intended adjustment range.
When to re-measure postpartum
Re-measure when your current nursing bra becomes uncomfortable, the band changes position, cup coverage changes, or your body changes noticeably. You do not need to add a fixed cup size simply because you are nursing.
Using the result responsibly
Use the estimate to choose a starting point, then compare it with the specific nursing bra's chart and actual fit. Different brands can grade cups and bands differently, and nursing-bra construction can change the fit compared with an everyday bra.