Sports Bra Guide: Finding the Right Size and Support Level
A sports bra that doesn't fit correctly can make training uncomfortable regardless of how good it looks. The most common mistake is choosing by clothing size rather than by measurement — sports bra sizing works differently from regular bras, and support level is a separate decision from fit. This guide covers both.
How to Measure Your Sports Bra Size
Band size (underbust): Measure around your ribcage, directly under your bust. The tape should be snug but not tight — you should be able to fit two fingers under it. Round to the nearest even number. The band provides 70–80% of the total support, so a loose band means poor support regardless of cup fit.
Cup size (bust): Measure around the fullest part of your bust. Subtract your band measurement from this number. The difference corresponds to a cup size: 1 cm = AA, 2 cm = A, 3 cm = B, 4 cm = C, 5 cm = D. For sports bras, cup sizing is less critical than in underwire bras — focus on band fit first.
Sports bra sizing note: Many women need to go up a band size compared to their regular bra. Sports bras have more compression, and a band that feels correct in a regular bra can feel too tight in a sports bra. Try on before deciding, or check the brand's sports-bra-specific size guidance.
Support Levels: Choosing by Activity
Low support (light compression): Suitable for yoga, Pilates, Barre, walking, and light stretching. A lightly padded bralette or minimal-coverage sports bra works well. Movement is controlled and low-impact, so bounce control is not the primary concern.
Medium support (moderate compression or encapsulation): Suitable for cycling, spin, HIIT, and hiking. Adjustable straps are useful here for customizing fit to your proportions.
High support (maximum compression and/or encapsulation): Essential for running, jumping, aerobics, and high-impact training. Wide straps, a strong band, and compression or encapsulation construction. Racerback construction helps keep straps in place during overhead movements.
For a full breakdown by workout, see our sports bra guide for every workout. For complete sets, see our matching activewear sets guide.
Signs Your Sports Bra Fits Correctly
The band sits level all the way around and doesn't ride up during movement. Straps don't dig in or slip off. You can breathe fully and deeply without restriction. During activity, breast movement feels supported and controlled.
Signs Your Sports Bra Does Not Fit
Band rides up: band too loose. Straps dig in: band too loose (straps overcompensating). Cups gap: cup too large. Spillage: cup too small. Difficulty breathing: band too tight. Explore the HEY HONEY Sports Bra range or coordinated sets in the Mix & Match collection.
Find your support level.
Frequently Asked Questions
How do I know what sports bra size I am?
Measure your underbust (ribcage directly under your bust) for band size, and your bust (fullest point) for cup reference. Subtract underbust from bust — the difference in cm gives an approximate cup size. Band fit is the priority: the band provides most of the support. If between sizes, try both and judge by how the band feels during movement rather than standing still.
What is the difference between low, medium, and high support sports bras?
Low support: light compression for yoga, Pilates, and Barre. Medium support: moderate compression or encapsulation for cycling, HIIT, and hiking. High support: maximum compression and/or full encapsulation for running, jumping, and aerobics. Using a low-support bra for high-impact training is uncomfortable and can cause long-term tissue strain.
Should I size up or down in sports bras compared to my regular bra?
Many women need to go up one band size in sports bras. Sports bras have more compression than underwire bras, and a band that feels correct in a regular bra can feel too tight in a sports bra during deep breathing. If your regular bra is 75B, try 80B in a sports bra first. This varies by brand, so always check the specific guidance.
How tight should a sports bra be?
The band should be firm — snug enough that it doesn't move during activity, but not so tight that it restricts breathing or leaves marks. Test: take a full deep breath. You should be able to fully expand your ribcage. If you can't, the band is too tight. You should be able to fit two fingers under each strap.
