What nursing bra size should I buy? A simple guide.

You find out you’re pregnant. It’s a life changing moment for every mom-to-be.

Then comes a flurry of everything else – morning (all day) sickness, achy breasts, doctors’ appointments, getting the nursery ready etc. and weighing up if you want to breastfeed.

Regardless, you can wear nursing bras during pregnancy. These days, most maternity bras also double up as nursing bras anyway.

What’s more important is wearing a bra that fits you just right. So, let’s dive right into how you can get that perfect nursing bra.

What is the difference between band size and cup size?

The bra sizing system is a measure of the bust and rib cage circumference, stated in numbers and letters. The number portion of the size represents your band size or the measurement around your ribcage.

The letter portion is your cup size. You get your cup size by substracting your band size from your bust size. Your bust size is  the measurement around your chest at nipple level.

When to get measured for a nursing bra?

There is a well-known statistic that says 8 out of 10 women are wearing the wrong bra size but is there actually ‘a right size‘? The issue isn’t actually the incorrect size but that moms don’t know how to measure themselves and check for the best fit.

Our bodies undergo major changes during pregnancy and our breasts grow bigger and fuller as the pregnancy progresses. Our rib cage also expands and is largest just before delivery.

You can use your regular bra size as a guide but you will almost definitely need to measure yourself while pregnant to determine your nursing bra size.

When should you do this? Preferably during the 8th month of pregnancy for most accurate results. 

The 8th month of pregnancy

The last trimester is the best time to get fitted for nursing bras because you’ve gained most of your baby weight by now and your breasts should be the size it will be about 8 weeks post-delivery after your milk production stabilizes.

Anytime during pregnancy

But what if you can’t wait that long? I started wearing nursing bras a few weeks into my pregnancy. My breasts started changing and my regular bra just felt too restrictive.

You can measure yourself and wear nursing bras at anytime during your pregnancy. Just be aware that if you get measured too early, your bra might not fit later on in the pregnancy and after delivery.

I thought it was worth the risk for the extra months of comfort when I was wretched with morning sickness.

So, let’s get into the most important part:

How do I determine my nursing bra size while pregnant?

You have 2 options:

  1. You can get professionally measured in any lingerie boutique.

This may be the easier option, but you would have to subject yourself to someone invading your private space to measure your breasts. You would also feel obligated to buy from their limited selection.

  • Measure yourself at home

This is more fun. You can do it in the privacy of your own home at whatever time you choose. Then you get to go online-shopping, which is the best part.

It can be a bit confusing. There’s numbers and letters involved. And you actually need to do subtractions!

Don’t worry. Even with baby brain, you will be able to follow this simple step-by-step guide.

  1. First, get your tools ready. You will need:
  • A measuring tape
  • Pen and paper

2. Wear a non-padded bra (if you don’t have one, go braless)

3. Use the tape to measure your ribcage. This is the line directly under your breasts. The tape measure should sit horizontally around your chest and be snug but not tight.

4. Read the measurement in inches and round it up to the nearest even number. For example, if you measured 33 inches, round it up to 34 inches. Write it down. This is your band size.   

5. Measure the fullest part of your bust. Again, make sure the tape sits horizontally around your chest. Take down this measurement in inches.

6. Subtract your band size from your breast measurement. Each whole number difference is one cup size.   

For example, if your band measurement is 34 inches and your bust measurement is 38 inches, 38 minus 34 is 4. Your cup size is D.

This table shows the different cup sizes that correlate with your number: 

1 2 3 4 5 6 7
A B C D E F G

7. Your bra size is your band size and your cup size. Continuing on with this example, your bra size is 34D. 

That was easy enough, wasn’t it?

Can’t get your head around the arithmetic? Use this easy bra size calculator.

Need more help? This video illustrates how easy it is to measure yourself at home:

How to determine the right nursing bra size to buy

Now that we have learned about the ABC’s and the 123’s of bra measurements, how do we decide on the right nursing bra to buy?

If you’re not sure what type of nursing bra to buy, read our guide on how to choose the right nursing bra for you

Generally, you shouldn’t go wrong if you buy according to the measurements you got. But you can be different sizes in different bras depending on the type of bra and brand. The best thing would be to try on as many bras as possible to find a style and fit that you like. Just make sure that you can return them easily. One good way is to use Amazon Prime. You can order a few bras to try in the comfort of your own home and return whatever doesn’t suit.

How should a nursing bra fit?

  • The under-bust band

The under-bust band should fit perfectly around your ribcage, meaning it should not be too tight and should sit flat. You should be able to run 2 fingers beneath the band. The band provides the most support so it can’t be too loose. Look for bands with multiple hook and eye options (6 is a good number) or bra extenders so you can adjust accordingly.  

  • The shoulder straps

The straps should be wide so it doesn’t dig into your skin. It can’t be too loose or else it won’t offer any support. Again, the 2-finger-rule applies. You should be able to fit 2 fingers underneath each strap. If under-bust band is riding up, this is a sign your straps are done up too tightly.

Your bra shouldn’t leave marks on your skin when you remove it. 

  • The cups 

Your breasts should be fully contained and not spilling out on the sides or over the top. The cups should not be loose or wrinkly either

  • Center seam

The center part of a well-fitting nursing bra will lie flat against your chest. If it’s gaping in the middle, it’s the wrong bra for you.

Why is it important to wear a well-fitting nursing bra?

The last trimester and the first 8 weeks after your baby is born is hectic for any mom. Comfort, support and convenience is key during this time.

  • You will be wearing your nursing bra day and night, especially in the first 4weeks. So make sure you have a comfy one.
  • A bra that is too tight or doesn’t fit right will prevent milk flow and can eventually cause clogged milk ducts. The physical and emotional pain with clogged ducts and mastitis is unimaginable. you want to prevent this at all cost.  
  • Your breasts will be heavy with milk and you need a good fitting bra to support this weight.
  • Imagine holding a screaming baby with one hand who only wants that milk to flow. Now, imagine you struggling to let your breasts out as fast as you can! With a great fitting nursing bra, you can get your breasts out easily with one hand. This means happy baby and a happy mama.

To wrap up

I hope this article helps you decide what nursing bra size you should buy. The numbers and letters for bra sizes isn’t scary. With the right knowledge of how our bras should fit, it’s one less stress you have to deal with.

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