How To Measure For First Bra: A Parent's Step-by-Step Guide

Knowing how to measure for a first bra takes the guesswork out of an exciting milestone. You might be considering a bra if you've noticed some changes, like your breasts moving when you run or your nipples becoming more visible through your clothes. But choosing a bra isn't just about the colour or design. You need to find the right size.

Wearing the wrong size can lead to poor support and even back pain. On the other hand, a well-fitted bra can offer proper support as you grow, and it might even help your posture. All you need is a soft tape measure and two measurements, or you can use our first bra size calculator to work it out in seconds. View our full range of teen bras here.

When To Buy Your First Bra

First things first, how do you know when it's time to buy your first bra?

There isn't a simple answer to this question, as it's completely down to personal preferences. Some pre-teens may decide to begin wearing a bra from the age of 9, when they begin to feel uncomfortable changing for PE without the added cover of a bra.

Others choose to wait until their breast tissue begins to grow, which can happen any time between the ages of 8 and 14 years. At this point, you may notice that your breasts begin to move when you run, or that your nipples may begin to show through your clothing.

Ultimately, when you decide to buy your first bra will come down to individual preferences, and there is no right or wrong answer.

Measuring For Your First Bra

To measure for your first bra, you will need to work out both your band and cup size. To do this, you will need to have a flexible tape measure which you will be using to measure both your rib cage and your bust.

Measuring Your Band Size

First, wrap your tape measure around your rib cage, directly under your bust. The tape measure should lie exactly where the band of your bra would naturally sit. It should be level and snug. This measurement in inches is your band size.

This is where many high street stores go wrong as they are renowned for adding several inches to this measurement. This is because back in the 1950s, bras were made from silk and satin and did not stretch. However, fast-forward to the 21st century and our bras now allow for stretch, so we don't need to add anything onto this measurement.

So, if your rib cage measurement is 30 inches, your band size is 30. If the number is an odd number, you might need to try both the band sizes above and below to see which fits you best.

Measuring Your Cup Size

Next, wrap a measuring tape around the fullest part of your bust, level with your nipple, and then round the number in inches to the nearest whole number. You will then need to subtract your band measurement from this number.

So, if your bust measurement is 36" and your band measurement is 30", you'll do the calculation 36-30 and be left with 6". You can then use the table below to discover your cup size. In this example, your bra size would be 30E.

How To Measure Your Daughter For Her First Bra

If you are helping your daughter measure for her first bra, the steps are exactly the same as above. What makes the difference is how the moment feels, since a first bra fitting can feel a little awkward at this age, and you want your daughter's first bra to be a positive experience.

• Let her choose how it happens. Some girls are happy for a parent to take the measurements, others would rather do it themselves in private with the tape and the table above. Both work.
• Measure over a thin vest or crop top. Measurements taken over a soft, thin layer are close enough for a first bra and feel less exposing.
• Keep the tape level and snug. For the band, the tape sits around the rib cage directly under the bust. For the bust, it goes around the fullest part. Check it has not slipped at the back.
• Treat the result as a starting point. Try the size on, check the fit together using the guide below, and expect to re-measure every few months while she is still growing.

If she would rather be measured by someone else, a fitter can take the measurements, or she can measure herself at home and shop online in private.

How To Measure For A Training Bra

A training bra is usually the first step before a cupped bra, and it is measured in the same way. Take the band measurement around the rib cage under the bust, then the bust measurement around the fullest part.

If the difference between the two is less than an inch, a training bra or crop top sized by the band measurement, or by a simple small, medium or large size, is usually the right fit, since there is little need for a shaped cup yet. Once the difference reaches around an inch or more, a soft cupped first bra in an AA or A cup will start to fit better. Always check the band sits level and comfortable, and choose a style with adjustable straps so it can be loosened or tightened as she grows.

How Do Bra Sizes Work?

Bra sizes can seem complicated, especially if you've never bought a bra before. They combine both a number and letter together, which can feel daunting at first. We're going to explain exactly what that number and letter mean, giving you a clear understanding of how bra sizes work.

Your bra size begins with a number, such as 28, 30 or 32. These numbers go up in increments of 2, so you'll never see an odd number within a bra size. This number refers to the band size of your bra. This is the measurement of your ribcage in inches. So, if you have a band size of 30, this means that your ribcage is 30 inches in circumference.

The band size is followed by a letter which represents your cup size, for example B, DD or G. This refers to the size of your breasts in relation to the size of your rib cage. For the full picture, including sister sizes, see our guide to bra sizes explained.

What Bra Size Should A 13, 14 Or 15 Year Old Be?

There is no normal bra size for any age. Breasts develop at different times and to different sizes, so two girls the same age can easily be several cup sizes apart, and both are completely normal. A 13 year old might be a 28AA, while a 15 year old could just as easily be a 30A or a 32D.

Sizes such as 30A, 32A and 32B are common first bra sizes, but they are not a target. A 32A, for example, is a perfectly normal size for a 14 year old, and so is a smaller or larger one. The only way to know the right size is to measure, which is why it is worth ignoring age charts and using the band and bust method above instead.

How To Choose Your First Bra

There are many different types of bras for teens, and the type you'll choose will depend on your personal preferences. Comfort comes first, and the best first bra is usually a soft, non-wired style with adjustable straps. In this section, we'll talk you through the options available when choosing your first bra.

Training bras and crop tops

Basic support, cover and comfort before a cupped bra is needed, like the Royce Lola crop top.

Non-wired bras

A soft cup that supports without a wire, comfortable and natural. The Royce My First Bra is made for this stage. See all non-wired bras.

Bralettes

A soft, unpadded, non-wired bra, often in pretty lace or cotton. A popular step up once a crop top feels too simple.

U

Underwired bras

A U-shaped wire built into the cup adds support and shape. Usually for older teens, and only once the fit is right.

Sports bras

Reduce bounce and protect developing ligaments during exercise, like the adjustable Royce Impact Free.

P

Padded bras

Lightly padded cups give a smooth, rounded shape under thin school tops and add a little modesty.

First bras we recommend

Royce My First Bra

A soft, non-wired first bra in a two pack, made for the very first stage with gentle support and adjustable straps.

View the 2 pack →

Royce Sophia Teen Bra

A lightly moulded, non-wired teen bra that gives a smooth shape under school tops once a cup starts to be needed.

View Sophia →

Royce Lola Crop Top

A soft crop top style that works as a training bra, giving light cover and comfort before a cupped bra is needed.

View Lola →

Shop all teen and first bras →

Checking The Fit Of Your Bra

The fit of your bra is far more important than the size on its label. You might find that you need to go up or down a size depending on the brand of the bra that you choose, so it's important to know how to check that your bra fits properly.

When you put on a bra, you'll need to start with a 'swoop and scoop'. To do this, reach into your bra cup and scoop your breast tissue from underneath your armpit so that it sits inside the cup. If you notice that your breast tissue is spilling out of the top of the cup after you have done a 'swoop and scoop', or if the wiring is pressing into your breast tissue, you may need a larger cup size.

Next, check how the band of the bra sits on your back. It should be level all the way round your ribcage, without riding up at the back. When the bra is fastened on the loosest hook, you should only be able to fit two fingers under the band. This will allow you to tighten the bra in the future, as the band loosens as it ages.

Finally, check how the straps fit on your shoulders. They should be tight enough that they don't slip off your shoulders, but loose enough that they don't take the weight of your breasts. This is because the support should be coming from the band of your bra rather than your straps, preventing back and shoulder pain.

Read our full fitting guide here

What If Your Breasts Are Different Sizes?

Breasts come in all sorts of shapes and sizes, all of which are normal. Some people fit an AA cup whilst others require a K cup. There's no right or wrong size, only the size that's right for you. Our differences are what makes us all unique.

It's also completely normal for your breasts to be different sizes from each other. Some people may have breasts that are almost identical in size, whilst others may have breasts which vary by a cup size or more.

If your breasts are different sizes, you'll need to fit your bra to suit the larger breast. This is because breast tissue can be damaged by wearing a bra which is too small.

Can Teens Wear Underwired Bras?

Non-wired bras are usually the recommended style for teens for two reasons. Firstly, wearing a bra can take some getting used to. Non-wired bras are often more comfortable than underwired bras, so you're likely to find these bras easier to wear as a first bra.

Secondly, if your bra doesn't fit properly, the wire may dig into your breast. Whilst underwired bras are completely safe if fitted properly, they can also damage the breast tissue if the bra becomes too small.

As a teen, your breasts will continue growing for several years. Whilst a bra may fit perfectly one day, within a couple of weeks your breasts may have grown. Choosing a non-wired bra will mean that your bras last longer and there won't be anything uncomfortable digging into your breast as you grow and develop.

Older teens may prefer to wear an underwired bra for the additional support and shape that the style offers. It's especially important to ensure that the bra fits correctly if a teen does decide to opt for an underwired bra.

How To Tell When You Need To Buy A New Bra

As a teen, your breasts will be constantly changing. In fact, even once you reach adulthood, your breasts will continue to change as a result of hormones, illness and even the amount of water that you drink. As a result, you might find that your bra no longer fits quite right. That's because your breasts have changed since you last checked the fit.

You'll need to check the fit of your bra regularly to ensure that it offers you the right level of support and comfort, without digging into your breasts. If you find that your bra is no longer fitting quite right, it's time to buy a new bra.

View our full range of teen bras here

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