Many women buy a bra in one size and continue wearing that size for years, or even decades, without ever reassessing whether it still fits correctly. However, your body is constantly changing, and what fit perfectly five years ago may be completely wrong for you today. Understanding when and how often to remeasure your bra size ensures you're always wearing a size that provides optimal comfort and support.
Regular bra refitting isn't about vanity or chasing fashion—it's about maintaining your comfort, health, and confidence. A well-fitting bra impacts your posture, reduces back and shoulder pain, and helps clothing fit better. Here's everything you need to know about when to recalculate your size.
The General Rule: Every Six to Twelve Months
As a baseline, experts recommend having your bra size checked at least once every six to twelve months. This timeframe accounts for the gradual, often imperceptible changes that occur in our bodies due to aging, lifestyle factors, and natural fluctuations in weight and muscle tone.
You don't necessarily need to visit a professional fitter this often—our free Australian bra size calculator makes it easy to check your size at home in just a few minutes. Take your measurements following the correct technique, enter them into the calculator, and compare the results to your current size.
If your calculated size matches what you're wearing and your bras feel comfortable with no fit issues, you're all set. If there's a discrepancy, it's time to try some bras in your new size.
Weight Changes: More Than a Few Kilograms Matters
One of the most common triggers for bra size changes is weight fluctuation. Both weight gain and weight loss can significantly affect your bra size, changing your band size, cup size, or both.
As a general guideline, changes of approximately 4-5 kilograms or more often impact bra fit. However, where you carry weight matters too. Some women notice bra size changes with minimal overall weight change because their weight distribution has shifted.
If you've recently lost or gained weight, take fresh measurements and use our bra size calculator to check your size. Don't wait until your bras feel noticeably uncomfortable—subtle changes in fit that you've adjusted to might be more significant than you realise.
Pregnancy and Breastfeeding: Multiple Changes Ahead
Pregnancy initiates one of the most dramatic series of bra size changes a woman can experience. Starting as early as the first trimester, breast tissue begins to change in preparation for nursing. Many women go up one or more cup sizes before the baby even arrives.
During pregnancy, you may need to be refitted several times. The first trimester often brings initial changes, followed by further increases as pregnancy progresses. After birth, whether breastfeeding or not, your breasts will continue to change size.
Breastfeeding mothers often experience daily fluctuations in breast size depending on feeding schedules. Nursing bras with stretch or adjustable features accommodate these changes. Once you've finished breastfeeding, give your body a few months to settle before investing in new everyday bras, as your size may continue to adjust.
Menopause and Hormonal Changes
Hormonal shifts during perimenopause and menopause often affect breast tissue. Some women experience an increase in breast size as hormonal changes alter fat distribution. Others notice their breasts decrease in volume or change in density, becoming softer or less firm.
These changes don't happen overnight—they occur gradually over months or years. Regular size checks during this life stage help you keep pace with your changing body. Many post-menopausal women find their bra needs shift, often preferring different styles that suit their changed breast shape and support needs.
Beyond menopause, any hormonal changes—whether from medical treatments, starting or stopping hormonal contraception, or other factors—can potentially affect breast tissue and bra size.
Significant Exercise Changes
Starting a new exercise routine, particularly one involving upper body strength training, can change your band size and possibly your cup size. Building chest muscles can alter your ribcage measurement, while fat loss and muscle gain elsewhere can change your overall proportions.
Swimmers, rowers, and other athletes who develop significant lat muscles often find their band size increases even if their weight remains stable. Conversely, those who lose significant body fat through exercise may find both their band and cup sizes decrease.
If you've recently made major changes to your fitness routine and maintained them for a few months, it's worth rechecking your bra size to ensure your workout hasn't rendered your lingerie drawer obsolete.
Your Bras Are Giving You Signs
Beyond scheduled check-ins, your bras themselves will tell you when it's time to remeasure. Pay attention to these warning signs:
Constant adjusting throughout the day suggests something is off with your fit. Whether you're pulling up straps, tugging down bands, or repositioning cups, a well-fitting bra should stay put without frequent intervention.
New discomfort from bras that previously felt fine indicates your body has changed. If bras that once felt perfect now dig in, create marks, or feel too loose, your size has likely shifted.
Always needing to use the tightest hook on relatively new bras (less than six months old) suggests your band size has increased. New bras should fit on the loosest hook, giving you room to tighten as they stretch.
Don't Forget Your Bras Age Too
While reassessing your size, also consider the condition of your bras. Even if your size hasn't changed, bras wear out over time. Elastic relaxes, cups lose their shape, and underwires can become misshapen or pop through fabric.
A bra that fit perfectly when new may feel wrong after a year of regular wear simply because the bra itself has degraded. Most bras last approximately six months to a year with regular rotation, though this varies based on quality, care, and how often each bra is worn.
If you're having fit issues but your calculated size remains unchanged, the problem might be your bras rather than your body.
Making Refitting a Habit
The easiest way to stay on top of your bra size is to build regular checks into your routine. Consider measuring yourself at the change of seasons—it only takes a few minutes with our Australian bra size calculator and keeps you aware of any changes.
Keep a record of your measurements over time. This helps you spot trends and understand how your body responds to different life events. Some women discover their size fluctuates predictably throughout the year or with their menstrual cycle.
Remember, wearing the right bra size isn't a one-time achievement—it's an ongoing practice that evolves with your body. Regular refitting ensures you always have the support, comfort, and confidence that comes with a perfectly fitting bra.