Ultimate Guide On How To Measure Bra Sizes and Find The Perfect Fit
Figuring out how to measure bra size at home can be a minefield. You've got to consider cup size measurement, brand, fabric, style, and strap width. Not to mention the eternal question, to underwire or not to underwire? If you've ever worn an ill-fitted bra, you know that it can ruin your favourite outfit and your entire day. Getting the perfect fit is essential for your comfort and breast and back health. It's also important to reassess how your bras fit as your shape changes due to life events such as pregnancy and breastfeeding or when you gain or lose weight. Additionally, breast size isn't the only thing you need to consider - you also need to know your shape.
Our ultimate bra sizing guide offers everything you need to know about:
- How to measure bra size
- Understand cup size measurement
- Things to consider for a better-fitting bra
- Everyday bra fitting problems and much more.
So whether you're looking for the best bras for a large bust or just trying to get your head around the different types of bras and what they do, this bra fitting guide is here to help.
- Are you wearing the right bra size?
- How do bra sizes work?
- How to measure bra size at home
- Types of breast sizes and shapes
- Bra glossary & terminology
- Tips for finding the perfect bra sizing
- Sister sizing and how it is calculated
- The types of bras you need in your wardrobe
- Wearing a bra: tips and tricks to solve common problems
- Measure bra sizes like a pro
Are You Wearing The Right Bra Size?
The best way to know whether you're wearing the right bra size is to check for the following tell-tale signs.
- Poking underwire from the side of your breasts
- A bra band that rides up
- Wrinkling cups every time you wear the bra
- You notice cup spillage
- Straps slipping off your shoulder
- A bra that hikes up every time you lift your arms
If you've noticed one or more of these bra-fitting issues, it's time to change. Either head to a professional bra fitter, or better still, bring out that measuring tape. Follow our step-by-step bra sizing guide, and learn how to measure your bra size at home.
How Do Bra Sizes Work?
Bra sizing is more complex than the numbers you find on your clothes, and it can change depending on what country you are in. Wondering, 'how do bra sizes work?' Don't worry - any bra in Australia will have a double-digit number followed by either one or two letters. These indicate the band size and the cup size - the size of the band that wraps around your ribs plus your bust size. Did you know that 80% of women are wearing the wrong-size bra? Get it right using our tips below!
Bra sizes explained
Bra sizing comes down to two key measurements - band (rib cage) and cup (overbust). The cup size measurement is essentially thus the difference between the rib cage and the bust. Don't forget that the cup size is proportionate to the band size. E.g. a C cup on a 10 band will be much smaller than a C cup on a 16 band.
How To Measure Bra Size At Home
Here's a quick step-by-step guide to measuring your bra size:
Step 1: Measure the band size
To get the correct bra sizing at home, start using your tape measure to find the length around your ribs, just under your bust. Make sure the tape is taut against your body but not tight. This measurement is the under-bust and will inform the size of your bra band. You want it to be tight enough to provide support but not too tight that you can't breathe easily! If your underbust measurement is below 33 inches, add about 5 inches to get your band size. If your underbust is over 33 inches, add only 3 inches to get your band size. Round up if you land on an odd number.
Step 2: Cup size measurement
Once you have your underbust measurement, take your overbust measurement by measuring around your back and the widest part of your breasts, usually at the nipple. This breast size measurement should be close but not as tight as the under-bust measurement. Do this by placing a simple, non-padded bra on and placing the tape around the fullest part of your bust so that it's sitting level and flat. Note how many inches you are, as this will determine your cup size.
Step 3: Calculate the cup size
To calculate your cup size, minus your band size from your overbust measurement - this difference will indicate your cup. These are the current bra sizes in Australia: 0 = AA, 1 = A, 2 = B, 3 = C, 4 = D, 5 = DD, 6 = F, 7 = FF, 8 = G, 9 = GG, 10 = H, 11 = HH, 12 = J, 13 = JJ, 14 = K and so on.
Step 4: Find out your bra size
Now that you have your band and cup size, put them together to get your bra size. So, if you measured a 36-inch band size and your cup size was 5 = DD, your bra size is 36DD.
Bra size chart in Australia
Here's a quick guide to bra sizes to help you choose like a pro.
Under bust (cm)
Cup A (cm)
Cup B (cm)
Cup C (cm)
Cup D (cm)
Cup DD (cm)
Cup E (cm)
Cup F (cm)
Cup G (cm)
Cup H (cm)
If your breast measurements aren't landing exactly on these numbers, round up and not down. If your sizes are larger than these, it is best to go into a store and get professionally fitted. The larger the breasts are, the more natural variation you will find.
Types Of Breast Sizes And Shapes
Now that you know your bra sizing, it's time to figure out your breast shape. According to bra experts Triumph, there are nine common shapes:
- Relaxed-shaped breasts have a softer appearance and tend to hang a little more.
- Asymmetrical breasts, where one breast is noticeably bigger than the other.
- Athletic breasts, which are smaller and more muscular, don't require as much support.
- Slender breasts, which get narrower towards the bottom.
- Bell-shaped breasts, which are fuller at the bottom.
- East-west breast, with nipples pointing in opposite directions.
- Side-set breasts, which sit to the sides of the chest.
- Round breasts, which are, well, round. They're often naturally well-supported but may need fuller coverage around the top.
- Teardrop breasts, which are fuller below the nipple.
How to size up or down correctly
Need to go down one cup size for a better fit? The best way to do this is to go up one band size. For instance, if you're a 34C and want to go up one cup size, opt for a 36B. Always remember that bra sizing can change slightly from one brand to another. And there's an element of trial and error involved until you find that perfect fitting bra.
Bra Glossary & Terminology
Refers to where the shoulder strap connects with the bra cup.
The balconette refers to a bra shape that appears higher towards the front centre and broader at the apexes.
Bralettes are soft cup bras that are typically wire-free. Generally speaking, they provide less support than a traditional bra, but this is only sometimes the case.
Boning is made of materials like metal or plastic. They are flexible or very rigid and used on a bra's side panels.
Cantilever is a specialised anchoring technique used to construct bras. It involves attaching the shoulder straps to the back of the bra using an extra section of the shoulder strap, lace, or fabric.
Contour bras are a popular lingerie item designed with either moulded foam or spacer cups for added comfort, shaping, smoothness and support.
Control garments feature high-performance fabrics with a high elastane content, designed to alter the wearer's shape or silhouette.
These bras offer various style options, including crisscrossed, halter, and strapless styles.
Demi cup bras are lingerie types that provide minimal coverage of the bust and are sometimes referred to as ¾ cup bras.
Embroidery is a type of decorative art involving stitching on top of a substrate, such as mesh or fabric, often using intricate designs and motifs. The technique has been employed for centuries, with finds of early examples dating back to antiquity. Embroidery is still widely used in the fashion and textiles industry today.
A foam cup is a type of padding used in bras to provide support and shape. This padding can be manipulated through moulding or stitching.
Hook and eye
Hook and eye closure is a small metal fastener commonly used to secure the closure of a brassiere.
Moulding is a process where materials such as foam and fabric are heated and then pressed into the desired shape using a top plate and lower plate. This technique is used to create items such as contour cups made from foam, and moulded cups, constructed from fabric.
The pushup bra is an undergarment designed to enhance the bust. It typically features padded or contour cups to lift the bust and close-set wires to bring the breasts closer together.
Expert Tips For Finding The Perfect Fitting Bra
Bra shopping and wearing can be a tedious, uncomfortable experience for many women. Ill-fitting bras can dig into the skin, slip off shoulders, and create unflattering spillage--causing the wearer to remove them the second they enter the house.
Read on for 7 top tips for the perfect bra fitting and measurements.
- Cup size is a critical factor in bust support, with the band providing approximately 90 per cent. Straps are not primarily used to firm up the bust but to keep it flush with the body and enhance its shape. If the cup and band fit correctly, most bras should remain in place even after removing the straps.
- The centre gore of the bra should sit flush against your chest, this ensures that the cups and underwire are properly supporting your bust.
- When purchasing bras, experts advise women to be aware of their proper size and sister sizes. This is due to the wide variation in how a bra of the same size fits from one brand or style to another. To ensure you get a good fit, keep in mind that if you go up in the band, you should go down one cup size and vice versa. For instance, if you typically wear a 32C, try a 30D or 34B. Likewise, if your normal size is 34C, you may find better-fitting bras in a 36B or a 32D.
- The natural asymmetry of the female form is something that many women are familiar with, especially regarding breast sizes and shapes. In terms of breast sizes, if one is larger than the other, buy a bra that fits the bigger breast. You can purchase special fillers to go into the other cup; some bras even come with fillers you can take out instead!
- If your breasts extend beyond the cup, they may put additional pressure on the straps. As a result, you may find yourself having to pull the straps to maintain them in place. In this situation, opting for a larger cup size measurement would likely provide relief for your shoulders.
- If the bra straps are causing discomfort and digging into your shoulder, it may indicate that the cups are too small. If the breasts protrude beyond the cup line, the added weight on the straps may cause users to pull them tauter. In either case, a larger cup size may provide better support and comfort for the shoulders.
- The other plausible explanation for straps digging into your shoulder is that the band size is too big. It may be worthwhile coming down one band size. To check the bra fitting, stand in front of a mirror and examine the position of the straps; if they are pulled too tight, the band is most likely too large or no longer supportive.
- Experiencing slipping straps? Large cup sizes could be a possible culprit. Ideally, if you notice the front of your bra, between the cups, floating, once you've put the bra on, you should go down one cup size to get a better-fitting bra.
5 ways to ensure your bra sizing is correct
Make sure your bra is fitting correctly by checking off the following points:
- The breasts are sitting comfortably in the cups and not spilling over.
- The underwire lies flat against the body when your arms are raised. The underwire should form a semi-circle under each breast, and sit flat in the centre against your chest.
- The band goes around your body horizontally and isn't raised at the back. The band should be snug and you should be able to fit two fingers under the hooks.
- Hook your bra and slip the straps off your shoulders - if the band is tight enough, the bra will stay in place (it's how strapless bras do their thing)
- The straps aren't falling off your shoulders or digging in too tightly.
Sister Bra Sizing And How It's Calculated
If you've been looking for the perfect bra, you may have come across the term 'sister sizing'. Sister sizing refers to other bra sizes where the volume of the cup stays the same, even though the band and bust size change. To measure the bra sister size, you need to move one step in either direction of your current bra size. For example, if you are a 12C, your sister sizes are 10D and 14B. So if you find you are using the looser hook on your bra and it's still a little tight, moving up in your sister size will provide you with a broader band but the same cup volume.
If you use the tightest hook you can, and it's still not tight enough, moving down a sister size will give you a tighter band with the same cup volume.
This works because bra sizing is a ratio of the band to your bust - how much breast tissue the cup can hold will increase as the band size increases. Cup size won't hold the same volume for all women, so you and your friend who are both the same cup will still have different breast sizes depending on your band size!
Pro tip: be careful with sister sizing
Try to only move up to one step when buying a sister-size bra - going too far will lead to bras that don't fit correctly.
Bra Style Guide: The Types Of Bras You Need In Your Wardrobe
Now that your bra measurement is sorted, here's a quick lowdown on a few must-have designs. No matter how much you love your favourite bra, you'll need a few different designs to get you through life! Here are some examples of when you'll need to switch up your bra design. Every bra type and material serves a different purpose, so it's worth investing in a few versatile and comfortable styles to help you navigate day to night. Investing in multiple bras also ensures you don't stretch out a bra too quickly. Here's what we recommend you have:
- T-Shirt Bras: If it's an everyday t-shirt bra you're after, there are a few varieties you can choose from. A t-shirt bra provides a smooth and comfortable fit that you can wear underneath tight-fitting clothing without showing if you have the correct size. Try the Berlei Barely There bra as a great t-shirt bra for everyday wear.
- A minimiser bra: helps minimise the appearance of the bust whilst providing superior support and shaping. Great for D+ cup sizes and supporting asymmetrical or teardrop-shaped breasts. The Triumph embroidered minimiser is a popular favourite.
- A sports bra: is a must-have to help offer more support and minimise bounce during physical activities. High-impact sports like netball, hockey and martial arts require a sports bra. The design minimises breast movement without impacting your physical performance and keeps you comfortable no matter what sport you're playing. If you are working out more than once a week, it's a good idea to have several so you can cycle through them without washing your bras repeatedly. Try the Berlei Electrify Bra for excellent bounce control and breathability.
- Convertible bra: if you love wearing racerback or halter neck style tops and dresses, a convertible bra is your best friend! Convertible bras allow you to change the style of the straps to match your outfit so you can wear your clothes confidently.
- Strapless bra: if you are wearing a strapless dress, then a strapless bra is what you need. It's imperative to get the correct band size for these bras, as they will do all the lifting without any straps to help out.
- Opt for a wireless bra: or bralette you can wear while travelling or lounging at home. Wireless bras also make great first bras for tweens and teens. The Playtex Ultimate Lift and Support bra is a wireless option for optimal comfort.
- Maternity bra: For the ultimate comfort and convenience during pregnancy and breastfeeding, a well-fitting maternity bra is a must. Maternity bras are usually wire-free, and feature wide straps to better support fluctuating breast size during pregnancy and after birth. Clips allow you to flip the cup down for easy, discreet breastfeeding. Remember, your maternity bras will have to withstand unexpected let-downs and the occasional baby spew, so make sure you have enough on rotation to allow for frequent washing, especially during the early days. Triumph makes fantastic maternity bras, in a range of colours and styles.
- Full coverage bras: When it comes to selecting a bra for a bigger bust, you can't go past Fayreform for full coverage bras. They've been the leader in D-G cups for almost a century, and have perfected the production of bras for busty ladies. A larger-sized bra doesn't need to look like the kind of scaffolding you'd expect to see at a construction site, either. Bigger-breasted ladies can find gorgeous bras with delicate lace detailing in the Fayreform range.
Pro tip: Choosing the best bra fabric for your needs
When you're out shopping for a bra - factor in the fabric and the technology too. To ensure you make the best selection, ask yourself specific questions about the fabric: Does it need to provide moisture-wicking capabilities? Is lace detail desired? Is there any sensitivity with the skin that requires a softer material?
Wearing A Bra: Tips And Tricks To Solve Common Problems
For something worn daily, bras can present quite a few problems! They can be tricky to put on, awkward to adjust and can make or break your entire outfit. Here are some of our favourite tips and tricks for wearing and adjusting bras:
- When you first put on a bra as a teenager, you probably didn't know or were too embarrassed to do it properly. But lifting your breasts into the cups is VITAL to wearing a bra comfortably and for health reasons. If you don't lift each breast into its cup, the bra will sit over the top rather than supporting them. This will lead to uncomfortable pressure on your breasts, plus they will pop out from underneath your bra when you lift your arms!
- If you are wearing a new bra for the first time, ensure it's fitted so you wear it on the loosest hook. Bras will stretch over time, and you can tighten it with another hook when this happens, which will extend the life of your bra.
- If your straps keep falling off, tightening them is the first solution you should try. If you have naturally sloping shoulders, a change in bra style may benefit you. A t-shirt or racerback style bra will help, as their straps are narrower than other styles and are less likely to slip off your shoulders.
- If your breasts aren't filling your bra cups, there is no need to panic. Try tightening the straps, as this may draw the top of the cup flush against your skin. If this doesn't work, you may need to purchase a new bra. Plunge-style bras can help with this, or you may need to go down a cup size.
- 'Swooping and Scooping' is a widely used professional technique in which you use your hands to scoop and properly place your bust into the bra cups to ensure optimal support.
Measure Bra Sizes Like a Pro and Find a Comfortable Bra For You
Measuring bra sizes may seem intimidating initially, but it can easily be achieved with a few simple steps. Our guide outlines the A-Z to bra sizing and bra measurement. Refer to our Australian Bra size chart for sizing guidance. Whether you need a new bra for going out, everyday wear, sport or if you've just worn through your old ones, Harris Scarfe's huge variety is sure to have the perfect bra for you!
Check out the whole range online or head to your nearest Harris Scarfe store, where our friendly team can fit you for the perfect bra, and you can shop your favourite brands, including Berlei Bras, Triumph Bras, Fayreform Bras and Playtex Bras. Need some more inspiration for your next outfit? Our fashion hub has heaps of great ideas on what's trending, or check out our extensive range of women's clothing, where you can find all the pieces you need to build your next knockout outfit!