Finding the right sports bra size can make a big difference in comfort, support, and movement during exercise. A sports bra that is too tight may feel restrictive, while one that is too loose may not provide enough support.
If you are wondering how to measure sports bra size, you can usually get a good starting point at home with a soft measuring tape. You will generally need two measurements: your underbust measurement and your bust measurement.
How Do You Measure Your Sports Bra Size?
To measure your sports bra size at home, follow these simple steps:
- Measure around your rib cage directly underneath your breasts.
- Measure around the fullest part of your breasts.
- Write down both measurements in inches or centimetres.
- Compare your measurements with the size chart provided by the sports bra brand.
- Consider the level of support and fit you need for your activity.
Different brands can use different sizing systems, so always check the manufacturer’s size chart before choosing a sports bra.
Step 1: Measure Your Underbust
The first measurement is your underbust, which is the area directly underneath your breasts where the lower band of the sports bra will sit.
To measure it:
- Stand upright and relax your shoulders.
- Wrap a soft measuring tape around your rib cage.
- Keep the tape directly underneath your breasts.
- Make sure the tape is level all the way around your body.
- Keep it snug but not uncomfortably tight.
- Record the measurement.
Do not pull the tape so tightly that it digs into your skin. The measurement should represent a firm but comfortable fit.
Step 2: Measure Your Bust
Next, measure around the fullest part of your breasts.
Place the measuring tape around your back and across the fullest part of your breasts. Keep the tape level and avoid pulling it tightly.
The tape should rest against your body without compressing your breasts.
Record this measurement separately from your underbust measurement.
Step 3: Use the Brand’s Sports Bra Size Chart
Once you have both measurements, compare them with the sports bra manufacturer’s size chart.
For example, a brand may provide sizes such as:
- XS
- S
- M
- L
- XL
- XXL
Some sports bras use traditional bra sizing such as 32C, 34D, or 36DD, while others use clothing-style sizes such as Small, Medium, or Large.
Because sizing varies between brands, there is no universal sports bra size chart that works perfectly for every manufacturer.
Should You Measure With a Bra On?
For the most accurate measurements, it is generally best to measure without a padded or heavily structured bra.
If you prefer to measure while wearing a bra, choose a thin, non-padded bra that does not significantly change the shape or size of your breasts.
A padded bra can add extra volume and may affect your bust measurement.
How Should a Sports Bra Fit?
Knowing your measurements is only the first step. Your sports bra should also feel comfortable when you move.
A properly fitting sports bra should generally:
- Hold your breasts securely without excessive compression.
- Have a band that feels snug but does not painfully dig into your ribs.
- Allow you to breathe comfortably.
- Keep the breasts supported during movement.
- Stay in place when you raise your arms.
- Avoid excessive gaps or loose areas.
- Have straps that do not continuously slip off your shoulders.
Try moving your arms, bending forward, and walking or jumping lightly when checking the fit.
How Tight Should a Sports Bra Be?
A sports bra should usually feel snug rather than painfully tight.
The band provides much of the support, so it should stay securely in place around your rib cage. However, it should not make breathing difficult or cause significant discomfort.
If you notice deep marks, rubbing, numbness, restricted breathing, or persistent discomfort, the sports bra may be too tight or may not be the right style for your body.
What If You Are Between Sports Bra Sizes?
If your measurements fall between two sizes, check the individual brand’s fitting recommendations.
You may also want to consider:
- Your breast volume and shape
- How much compression the bra provides
- The type of exercise you do
- Whether you prefer a snug or less restrictive fit
- The material and stretch of the sports bra
For high-impact activities such as running, you may want a sports bra designed specifically for high-impact support.
Does Activity Level Affect Sports Bra Size?
Your basic size does not necessarily change based on the activity you are doing, but the type and level of support you need can change.
For example:
Low-impact activities:
Yoga, stretching, walking, and casual activities may require lighter support.
Medium-impact activities:
Cycling, weight training, hiking, and similar activities may benefit from moderate support.
High-impact activities:
Running, jumping, aerobics, and other activities involving significant breast movement may require a high-support sports bra.
Choosing the appropriate support level can be just as important as choosing the correct size.
Can You Use Your Regular Bra Size for a Sports Bra?
Sometimes, but not always.
Some sports bras are sold using traditional bra sizing, while others use general clothing sizes. Even when two products use the same size label, their fit can be different.
Your regular bra size can provide a useful starting point, but measuring yourself and checking the specific brand’s size chart is usually more reliable.
What If Your Bust and Underbust Measurements Don’t Match the Size Chart?
This can happen, especially because bodies do not always fit neatly into standard size categories.
If your measurements do not correspond to one size, look at the brand’s recommendations for between sizes. Some brands also provide separate guidance based on cup and band measurements.
If possible, choose a retailer with a flexible return or exchange policy so you can try another size if the first one does not fit correctly.
Common Mistakes When Measuring for a Sports Bra
Avoid these common mistakes:
Measuring Over Thick Clothing
Bulky clothing can add extra measurement around your body and make your results less accurate.
Pulling the Tape Too Tight
A very tight tape can produce a smaller measurement than your actual body measurement.
Letting the Tape Become Uneven
The measuring tape should remain level around your body. If it slopes upward or downward, your measurement may be inaccurate.
Measuring With a Padded Bra
Padding can affect your bust measurement.
Ignoring the Brand’s Size Chart
A size Medium from one brand may fit differently from a Medium from another. Always check the manufacturer’s chart.
How Often Should You Measure Your Sports Bra Size?
You do not necessarily need to measure yourself every time you buy a sports bra. However, it can be useful to measure again if your body measurements have changed or if your existing bras no longer fit comfortably.
Changes in weight, body composition, pregnancy, or other normal body changes can affect how a sports bra fits.
Frequently Asked Questions
How do I measure my sports bra size at home?
Measure around your rib cage directly underneath your breasts to get your underbust measurement, then measure around the fullest part of your breasts for your bust measurement. Compare both measurements with the sports bra brand’s size chart.
Do you measure sports bras differently from regular bras?
The basic measurements can be similar, but sports bras may use different sizing systems. Some use band-and-cup sizing, while others use XS–XXL sizing. Always check the specific product’s size chart.
Should a sports bra be tighter than a normal bra?
A sports bra generally needs to provide a secure fit for support, but it should not be painfully tight or restrict your breathing. The correct fit should feel supportive while still allowing comfortable movement.
Should I measure my sports bra size with a bra on?
For a more accurate measurement, it is generally preferable to measure without a padded or heavily structured bra. If you wear a bra during measurement, choose a thin, non-padded style.
What is the most important measurement for a sports bra?
This depends on the sports bra’s sizing system. For traditional bra sizing, both your underbust and bust measurements are important. For XS–XXL sports bras, the manufacturer’s size chart may use bust, underbust, or other body measurements.
Can sports bra sizes vary between brands?
Yes. Sports bra sizing is not completely standardised between brands, so the same labelled size may fit differently across manufacturers. Checking the brand’s own size chart is important.
Final Thoughts
Learning how to measure sports bra size is relatively simple. Start by measuring your underbust directly beneath your breasts and then measure around the fullest part of your bust. Once you have both measurements, compare them with the specific brand’s size chart.
Remember that the correct size is only part of finding a good sports bra. The style, support level, fabric, straps, band, and intended activity can all affect how comfortable and supportive it feels.
If a sports bra causes significant discomfort, restricts your breathing, digs painfully into your skin, or does not stay securely in place, consider trying a different size or style.