Your Body's Changing.
Your Bra Should Too.
Band and cup size both shift during pregnancy and nursing often more than once. Enter your pre-pregnancy size and current stage to get an estimated size range to try next.
- ✓ Results in under a minute, no sign-up needed
- ✓ Covers pregnancy trimesters and nursing stage
- ✓ Gives a size range, not just one number
Estimate your maternity size
Enter your usual (pre-pregnancy) size and current stage.
Why Maternity Sizing Is Different
The ribcage expands gradually through pregnancy (adding to band size) while breast tissue grows independently for milk production (adding to cup size) the two changes don't happen at the same rate, which is why a single "add one size" rule doesn't work well. Most guides suggest re-measuring every trimester, and again a few weeks after milk supply regulates postpartum, since size often shifts again at that point.
What to Expect, Stage by Stage
- 1st trimester: tenderness and slight growth usually the same band, possibly one cup up.
- 2nd–3rd trimester: rib cage expands typically one to two band sizes up, one to two cups up.
- Nursing / postpartum: size fluctuates with milk supply a nursing bra with extra hook rows helps here.
- After breastfeeding ends: re-measure again size often settles differently than both your pre- and during-pregnancy numbers.
Frequently Asked Questions
Should I buy maternity bras early?
Most people switch once their usual bra feels tight or uncomfortable, often around the 2nd trimester buying one size with extra hook rows helps it last longer.
Is a nursing bra the same as a maternity bra?
They overlap, but nursing bras add a clip-down cup for feeding access many are labelled and usable for both stages.
Will my size go back to normal after nursing?
Often close, but not always identical re-measuring once breastfeeding ends is the only reliable way to know.