How to Measure Your Bra Size at Home: Easy Guide
How to Measure Your Bra Size at Home: A Step-by-Step Guide
Did you know that approximately 80% of women wear the wrong bra size? You’re not alone if you’ve ever felt uncomfortable in a bra that doesn’t fit quite right. Whether it’s straps digging into your shoulders, a band that rides up, or cups that gap, an ill-fitting bra can affect your comfort, confidence, and even your posture throughout the day.
The good news? Learning how to measure your bra size at home is simple, free, and takes just a few minutes. With a soft measuring tape and this step-by-step guide, you’ll discover your true size and finally experience the comfort and support you deserve.
What You’ll Need
Before you start measuring, gather these essential items:
- A soft measuring tape (the kind used for sewing, not a rigid ruler)
- A mirror (optional but helpful for accuracy)
- A well-fitting unlined bra or no bra at all (avoid padded bras, which can skew measurements)
- Comfortable clothing (wear what you normally wear — this won’t affect measurements)
- Someone to help (optional, but helpful for ensuring tape is level and snug)
Step 1: Measure Your Band Size
Your band size is the foundation of your bra fit. Follow these steps to measure accurately:
- Remove your bra. For the most accurate measurement, stand in front of a mirror without your bra on, or wearing a lightweight bra only.
- Stand straight and relaxed. Keep your posture natural — don’t slouch or puff out your chest.
- Place the measuring tape around your ribcage. Position the tape horizontally just underneath your bust, directly under your bra band would sit.
- Keep the tape snug but not tight. The tape should feel firm against your skin but not dig in or compress. You should be able to fit one finger under the tape comfortably.
- Take the measurement. Note this number in inches.
- Round to the nearest even number. If your measurement is 32.5 inches, round down to 32. If it’s 33.5 inches, round up to 34. This is your band size.
Example: If your underbust measurement is 32.75 inches, your band size is 32. If it’s 33.25 inches, your band size is 34.
Step 2: Measure Your Bust Size
Now that you have your band size, it’s time to measure your bust. This measurement will help us determine your cup size.
- Keep the measuring tape loose. You’re now measuring around the fullest part of your bust, so the tape should be relaxed and level.
- Position the tape across your chest. Wrap the measuring tape around the fullest part of your bust. For most women, this sits at your nipple line.
- Stand straight and look ahead. Keep your shoulders relaxed and your posture natural.
- Make sure the tape is level. The tape should be parallel to the ground on all sides. Check this in the mirror if possible.
- Don’t pull the tape tight. It should sit gently against your skin without any tension.
- Take the measurement. Note this number in inches. Unlike your band measurement, you do not round your bust measurement.
Example: If your bust measurement is 36.5 inches, keep it as 36.5 (not 37).
Step 3: Calculate Your Cup Size
Your cup size is determined by the difference between your bust measurement and your band measurement. This is where the magic happens!
The formula is simple:
Bust Measurement — Band Measurement = Cup Size
Example: If your bust measures 37 inches and your band is 32 inches, the difference is 5 inches, which equals a DD/E cup.
Cup Size Calculation Chart
Use this chart to convert your measurement difference into your cup size:
| Difference (inches) | Cup Size | Example (32-band) |
|---|---|---|
| 0” | AA | 32AA |
| 1” | A | 32A |
| 2” | B | 32B |
| 3” | C | 32C |
| 4” | D | 32D |
| 5” | DD / E | 32DD or 32E |
| 6” | DDD / F | 32DDD or 32F |
| 7” | G | 32G |
| 8” | H | 32H |
Quick tip: Each inch of difference equals one cup size. So if you measure a 4-inch difference, you’re a D cup. If it’s 5 inches, you’re a DD/E cup. Simple!
Australian Bra Size Chart & International Conversions
Mavena Co. is based in Australia, and understanding Australian bra sizing standards is important. Here’s a comprehensive chart showing how Australian sizes compare to US, UK, and European sizing:
| Australian | US | UK | European | Band (cm) |
|---|---|---|---|---|
| 6AA | 28AA | 28AA | 60AA | 60 |
| 6A | 28A | 28A | 60A | 60 |
| 6B | 28B | 28B | 60B | 60 |
| 6C | 28C | 28C | 60C | 60 |
| 8AA | 30AA | 30AA | 65AA | 65 |
| 8A | 30A | 30A | 65A | 65 |
| 8B | 30B | 30B | 65B | 65 |
| 8C | 30C | 30C | 65C | 65 |
| 10AA | 32AA | 32AA | 70AA | 70 |
| 10A | 32A | 32A | 70A | 70 |
| 10B | 32B | 32B | 70B | 70 |
| 10C | 32C | 32C | 70C | 70 |
| 10D | 32D | 32D | 70D | 70 |
| 10DD | 32DD | 32E | 70E | 70 |
| 12AA | 34AA | 34AA | 75AA | 75 |
| 12A | 34A | 34A | 75A | 75 |
| 12B | 34B | 34B | 75B | 75 |
| 12C | 34C | 34C | 75C | 75 |
| 12D | 34D | 34D | 75D | 75 |
| 12DD | 34DD | 34E | 75E | 75 |
| 14AA | 36AA | 36AA | 80AA | 80 |
| 14A | 36A | 36A | 80A | 80 |
| 14B | 36B | 36B | 80B | 80 |
| 14C | 36C | 36C | 80C | 80 |
| 14D | 36D | 36D | 80D | 80 |
| 14DD | 36DD | 36E | 80E | 80 |
| 16AA | 38AA | 38AA | 85AA | 85 |
| 16A | 38A | 38A | 85A | 85 |
| 16B | 38B | 38B | 85B | 85 |
| 16C | 38C | 38C | 85C | 85 |
| 16D | 38D | 38D | 85D | 85 |
| 16DD | 38DD | 38E | 85E | 85 |
Key notes on Australian sizing:
- Australian sizes use even numbers for bands (6, 8, 10, 12, 14, 16 correspond to US 28, 30, 32, 34, 36, 38)
- Cup letters follow the same progression as US and UK sizing (A, B, C, D, DD/E, F, G, H)
- The UK uses E instead of DD for the fifth cup size, while Australia and the US use DD
- European sizing uses centimetres for band measurements (60 cm, 65 cm, 70 cm, etc.)
Understanding Sister Sizes
Even after you’ve found your perfect size, it’s helpful to understand the concept of “sister sizes.” Sister sizes are different bra sizes that have the same cup volume, just distributed across different band widths.
How sister sizes work:
When you go down one band size and up one cup size, you maintain the same volume. For example, a 34C has the same cup volume as a 32D or 36B. Similarly, when you go up one band size and down one cup size, you also maintain the same volume.
Why sister sizes matter:
- If your band size is between two numbers, sister sizes help you find comfort
- If a bra feels tight in the band but too loose in the cup, try sizing up the band and down the cup
- If a bra feels loose in the band but small in the cup, try sizing down the band and up the cup
- Sister sizes allow you to find your perfect fit even if your exact size isn’t available
| Larger Band | Your Size | Smaller Band |
|---|---|---|
| 36B | 34C | 32D |
| 36C | 34D | 32DD/E |
| 36D | 34DD/E | 32F |
| 38B | 36C | 34D |
| 38C | 36D | 34DD/E |
| 38D | 36DD/E | 34F |
Signs Your Bra Doesn’t Fit
Even with accurate measurements, it’s crucial to recognise the signs of a poorly fitting bra. Here’s what to look for:
Band Issues
- Band rides up at the back: This is the #1 sign your band is too loose. The back of your bra should sit at the same level as the front.
- Band feels too tight: You shouldn’t need to hold your breath or feel restricted. If digging in or leaving marks, you need a larger band.
- Band twists or rotates: This indicates an improper fit, usually a band that’s too loose or cups that are too tight.
Cup Issues
- Cups gap or wrinkle: If you see empty space in the cups, your cups are too large. Try sizing down.
- Breast spillage or quadboob effect: If breast tissue spills over the cup edges, your cups are too small. Try sizing up.
- Gore (center panel) floats away from your body: This indicates cups that are too small, or a band that’s too loose.
Strap Issues
-
Straps dig into shoulders: This usually means the cup is too small or id the band is too loose, causing your breasts to sag and straps to dig in.
-
Straps slip off shoulders: Either your band is too loose, or you need to adjust the strap position. Some bras have adjustable or convertible straps.
-
Straps feel tight or uncomfortable: If you can’t fit a finger under the strap, it’s too tight.
Popular Bra Types Explained
Now that you know your size, let’s explore different bra styles and find the ones that work best for your lifestyle and body type.
Push-Up Bras
Push-up bras add lift and create a fuller appearance through padding and an uplifted cup design. They’re perfect for low-cut tops or a the when you want extra confidence. Try our FlexForm Wireless Push-Up Bra for Women for comfortable, sculpted support throughout the day.
Wireless & Unlined Bras
Wireless bras offer comfort without the metal underwire, whilst unlined bras provide a natural shape and excellent support. They’re ideal for everyday wear and under fitted clothing. Our Unlined Underwire Lace Bra for Women combines comfort with delicate style.
Bralettes
Bralettes are wire-free, lightly structured bras that offer everyday comfort and support. They’re perfect for lounging, sleeping, or layering under loose-fitting clothes. Check out our Breathable Bralette Set for Women for ultimate comfort.
T-Shirt Bras
T-shirt bras have a smooth, seamless construction that won’t show under fitted clothing. They provide a rounded, natural shape and are a versatile staple in every woman’s lingerie drawer.
Strapless & Convertible Bras
Strapless bras are designed for off-shoulder or strapless tops. Convertible bras feature removable or adjustable straps for maximum versatility.
Sports Bras
Sports bras provide high support and minimal bounce during physical activity. They’re essential for comfort during exercise and should be measured separately from your regular bra size, as they typically run tighter.
Shelf Bras & Tankinis
Shelf bras are open-cup designs that provide support without coverage — they’re popular in fashion and swimwear. Our Ribbed Shelf Bra Tank Top for Women combines contemporary style with comfortable support.
Complement Your Bra with Perfect Shapewear
Once you’ve found your perfect-fitting bra, consider pairing it with shapewear for a smooth silhouette under fitted clothing. Our Shapewear Collection offers options for every body type and outfit.
For more detailed guidance, explore our comprehensive guides:
- Complete Guide to Shapewear — Everything you need to know about choosing the right shapewear
- Best Shapewear for Every Body Type — Find the perfect shapewear match for your unique silhouette
When to Get Remeasured
Your bra size isn't permanent. Several life events can change your measurements, and it’s important to remeasure regularly to maintain proper fit and support.
After Weight Changes
Even a 5-10 pound change can affect your bra size. If you’ve lost or gained weight, remeasure to ensure your bras still fit properly.
During & After Pregnancy
Pregnancy causes significant breast changes, beginning early in the first trimester. Your size may change multiple times throughout pregnancy and postpartum (especially if you’re breastfeeding). Remeasure every 2-3 months during pregnancy and after weaning.
Hormonal Changes
Hormonal fluctuations related to your menstrual cycle, hormonal contraceptives, or hormone replacement therapy can affect breast size and shape.
As You Age
Breast tissue changes naturally over time. What fit perfectly in your 20s may need adjustment in your 40s or 50s. Remeasure every 1-2 years as a general practice.
Every 1-2 Years
Even without major life changes, it’s good practice to remeasure every year or two. Bra fitting is not an exact science, and small adjustments can significantly improve comfort.
Frequently Asked Questions
Should I measure with or without a bra on?
For the most accurate measurements, measure without a bra. However, if you’re uncomfortable, wear a lightweight, unpadded bra. Padded, push-up, or heavily structured bras will distort your measurements. The key is to measure the natural contours of your ribcage and bust.
What if I’m between two band sizes?
If your measurements fall between two even numbers (for example, 33 inches), try both sizes. Many women find that sizing down and going up a cup size (using sister sizing) works better than the larger band. For example, if you’re between a 32 and 34, try both 32D and 34C. Pay attention to how the band fits and choose whichever feels more comfortable and supportive.
Does my bra size change if I gain or lose weight?
Yes, weight changes typically affect bra size, though not always proportionally. Losing weight usually means a smaller band and potentially smaller cups, whilst gaining weight often increases both. However, everyone’s body is different — some women might only see band changes, while others experience cup changes. Remeasure after significant weight fluctuations.
Is it normal for bra sizes to vary between brands?
Unfortunately, yes. Bra sizing is not standardised across brands, so a 34C from one manufacturer might fit differently than a 34C from another. This is why fit is more important than the number. Always try on bras when possible, and don’t assume your size is universal across brands.
How tight should my bra band be?
Your bra band should feel snug and supportive without being restrictive. You should be able to comfortably fit one finger under the band. If you can’t breathe, or if the band leaves red marks on your skin, it’s too tight. If the band rides up in the back, it’s too loose. The band should stay parallel to the ground at all times.
Can my cup size be different on each side?
Yes,his is completely normal. Most women have asymmetrical breasts, with one side slightly larger than the other. If the difference is significant, you might need to prioritise the larger breast when choosing a size. Alternatively, you can use bra inserts or padding on the smaller side to even out the appearance.
Your Perfect Fit Awaits
Now that you understand how to measure your bra size at home, you’re equipped with the knowledge to find your perfect fit. Remember, comfort and support are paramount — never settle for a bra that doesn’t make you feel confident and comfortable.
Take your time trying different styles and brands. Visit our curated collections of bras and intimates at Mavena Co., where quality and comfort are always guaranteed. Whether you’re looking for everyday support, special occasion glamour, or maximum comfort, we have the perfect bra waiting for you.
Ready to find your perfect bra? Start by measuring with this guide, then explore our collection of beautifully crafted bras designed for the modern Australian woman. Your comfort journey begins here.
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What We've Learned From Fitting Feedback
Our team has reviewed thousands of bra fitting questions from Australian women, and the most common issue is wearing the wrong band size. Many women wear a band that's too loose and cups that are too small — which affects both comfort and support.
Based on our sizing data, we've found that 85% of first-time customers who follow our measurement guide end up with a perfect fit on their first order. The key is measuring yourself without a bra on and standing naturally.
Our bestselling bra sizes in Australia cluster around 10C-12D, but we see huge demand across our full size range. Every body is different, which is exactly why at-home measuring matters so much.
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