Sports Bra Sizing
Sports Bra Size Calculator
Updated March 2026
Calculate your sports bra size based on your measurements and activity level. Get personalized support recommendations for low, medium, and high-impact workouts.
Find Your Sports Bra Size
Need your regular bra size first? Use our bra size calculator.
The right sports bra eliminates bounce and stays in place through any workout. Finding your size starts with your regular bra measurements.
How Sports Bra Sizing Differs
Sports bras prioritize support and motion control over aesthetics. The key differences from regular bras:
- The band should be snugger — the band provides 80% of support, and that matters even more during movement. A firm band stops the bra from riding up mid-workout.
- Cup shape is different — sports bras use compression, encapsulation, or a combination of both rather than traditional underwire construction.
- Sizing may differ by brand — many sports bras use S/M/L sizing, which maps roughly to band ranges (S = 30–32, M = 34–36, L = 38–40). Our calculator gives you the specific band-and-cup size so you can convert either way. See our brand sizing guide for specific brand fit notes.
Three Types of Sports Bra Support
Support Levels Explained
Finding the right sports bra size depends on both your measurements and the activity you need it for. Choosing the right support level is just as important as getting the right size. Match your bra to the impact level of your activity.
Different activities produce different levels of breast movement. Match your support level to your primary activity for the best combination of comfort and control.
Low Impact
Compression Bras
Best for yoga, walking, pilates, and casual cycling. These pull-on styles compress the bust against the chest wall for gentle support. Minimal structure, maximum comfort. Particularly suitable for A through C cups where less containment is needed. Look for soft fabrics, wide bottom bands, and racerback cuts.
Medium Impact
Encapsulation Bras
Best for hiking, weight training, skiing, cycling, and dancing. These bras have individual cups that support each breast separately, offering more structure and shape than compression styles. Wider straps distribute weight better during sustained activity. Recommended for all cup sizes, and the better choice for anyone D cup and above even in low-impact settings.
High Impact
Combination Bras
Essential for running, HIIT, jumping rope, tennis, and basketball. These combine both encapsulation and compression — individual molded cups plus an outer compression layer. A snug band is critical (consider sister sizing down one band). Look for wide adjustable straps, a hook-and-eye back closure, and moisture-wicking fabric. Non-negotiable for D cups and above.
When to Replace Your Sports Bra
Re-check your sports bra size every 6 to 12 months, because that is also when you should replace the bra itself. Unlike regular bras, sports bras lose their compression and elasticity faster because of the repeated stress of high-movement activity. After approximately 72 wears, the elastic fibers in the band and straps break down with washing and sweat exposure.
If the band has lost its snap-back, the straps slip without adjustment, or you feel bouncing you didn't notice before, it's time for a new one. Rotating between two or three sports bras extends the lifespan of each.
Frequently Asked Questions
Should I size down in a sports bra?
For high-impact activities like running, many fitters recommend going down one band size and up one cup size (sister sizing). This provides a snugger, more supportive fit without sacrificing cup volume. For low-impact activities like yoga or walking, your regular size is usually comfortable enough.
Can I use my regular bra size for sports bras?
Your regular size is a starting point, but your sports bra size may differ depending on the style. Compression styles may need sizing up for comfort, while encapsulation styles should match your measured size. Use our calculator above for a sports-specific recommendation tailored to your activity level.
What is the best sports bra for large busts?
For D cups and above, look for combination bras that offer both encapsulation (individual cups) and compression. Key features to prioritize: underwire or molded cups, wide padded straps, hook-and-eye back closure, and a snug band. Panache Sport and SheFit are frequently recommended by professional bra fitters for larger cup sizes.