Discover your perfect sports bra size with our accurate Sports Bra Size Calculator. Ensure optimal support during workouts to prevent injury and boost performance—ideal for women’s health and fitness in 2025.
Accurate Sizing
Professional calculation algorithm
Comfort Focused
Optimized for active lifestyles
Activity Specific
Recommendations by sport type
Enter Your Measurements
Your Sports Bra Size
Sister Sizes
Alternative sizes with similar cup volume. Useful if your calculated size isn’t available or doesn’t fit perfectly.
Recommended Sports Bra Styles
For your size and activity level, we recommend encapsulation-style bras with adjustable straps and wide bands for maximum support during high-impact activities.
Professional Fit Tips for Sports Bras
Band Should Be Snug But Comfortable
The band should sit parallel to the ground and not ride up. You should be able to fit two fingers underneath.
Minimal Breast Movement
During activity, breasts should move with your torso, not independently. Jump in place to test support.
Straps Shouldn’t Dig In
Adjust straps so they’re secure but don’t leave marks. Wider straps distribute weight better.
Check for Spillage
Ensure no breast tissue spills out the top, sides, or bottom of the bra during movement.
Sports Bra Size Chart
| Difference (inches/cm) | Cup Size | Recommended Support Level |
|---|---|---|
| 0-1 / 0-2.5 | AA | All impact levels |
| 1-2 / 2.5-5 | A | All impact levels |
| 2-3 / 5-7.5 | B | Medium to High impact |
| 3-4 / 7.5-10 | C | Medium to High impact |
| 4-5 / 10-12.5 | D | High impact required |
| 5-6 / 12.5-15 | DD/E | High impact required |
| 6-7 / 15-17.5 | DDD/F | Maximum support needed |
| 7-8 / 17.5-20 | G | Maximum support needed |
Activity Level Guide
Low Impact Activities
Yoga, Pilates, walking, strength training. Light to medium support bras work well.
Medium Impact Activities
Cycling, elliptical, hiking, dance. Medium to high support recommended.
High Impact Activities
Running, HIIT, jumping, team sports. Maximum support essential.
Finding the right sports bra size isn’t just about comfort—it’s about performance, posture, and breast health. Studies in 2024 by the British Journal of Sports Medicine revealed that nearly 70% of active women wear the wrong bra size, often leading to pain, discomfort, or reduced workout efficiency.
Our Sports Bra Size Calculator helps you accurately determine your band, cup, and support level in seconds. Whether you’re a runner, yogi, or strength trainer, this smart online tool uses precise measurement logic to match your bra size and support type to your activity intensity—ensuring total comfort, zero bounce, and improved athletic confidence.
Use it anywhere, anytime, and say goodbye to guesswork when buying your next sports bra.
How Sports Bra Size Calculator Works (Step by Step)
Using the Sports Bra Size Calculator is straightforward and user-friendly. Here’s a step-by-step guide to get accurate results:
- Select Your Measurement Unit: Choose between inches or centimeters for convenience. The tool automatically converts as needed (1 inch = 2.54 cm).
- Enter Underbust Measurement: Measure snugly around your ribcage just below your breasts. Input this value to determine your band size.
- Enter Bust Measurement: Measure around the fullest part of your bust. This helps calculate the cup size based on the difference from the underbust.
- Choose Activity Level: Select low impact (e.g., yoga, walking), medium impact (e.g., cycling, strength training), or high impact (e.g., running, HIIT) to receive tailored support recommendations.
- Calculate and Interpret Results: Click “Calculate Size” to get your bra size (e.g., 34C), sister sizes, style suggestions, and fit tips. The tool rounds the band to the nearest even number (clamped between 28-46) and assigns cups like AA for <1-inch difference or D for 4-5 inches. Results include activity-specific advice to ensure health benefits like reduced breast movement and injury risk.
Why Use This Sports Bra Size Calculator
This Sports Bra Size Calculator offers numerous health benefits by ensuring a proper fit that supports breast health and overall wellness during physical activity.
An ill-fitting sports bra can lead to discomfort, poor posture, back pain, and even increased risk of knee injuries like ACL tears, as recent studies from 2024 show. By providing accurate sizing, the tool helps prevent these issues, allowing you to focus on fitness goals without distraction.
Compared to manual estimation, which often leads to errors due to inconsistent measuring techniques, this online calculator uses standardized algorithms for precision and convenience. It’s accessible anytime, free, and incorporates activity levels for personalized recommendations—making it superior for busy women prioritizing health.
Evidence from biomechanical research in 2024-2025 highlights that proper support enhances exercise performance, reduces respiratory fatigue, and boosts confidence, aligning with WHO guidelines for regular physical activity to improve women’s health outcomes.
Understanding Your Sports Bra Size Results
When you receive your sports bra size calculation, you’ll see three key components: band size, cup size, and activity-specific recommendations. The band size represents the measurement around your ribcage, while the cup size indicates the difference between your bust and underbust measurements.
Your athletic bra size might differ from your everyday bra size due to the compression and encapsulation requirements of sports bras. Many women discover they need a different size for high-impact activities versus daily wear.
Health Benefits of Proper Sports Bra Fitting
Improved Posture and Breathing: A well-fitted sports bra allows for optimal ribcage expansion and diaphragmatic breathing, crucial for endurance activities. The American Physical Therapy Association emphasizes that proper breast support contributes to better overall spinal alignment during exercise.
Reduced Skin Irritation: Chafing and skin irritation from poorly fitted athletic bras can derail your fitness routine. Our sports bra calculator recommendations minimize friction points and ensure smooth, comfortable wear during even the longest workouts.
Enhanced Confidence and Motivation: When your sports bra fits perfectly, you can focus on your performance rather than adjusting your gear. This psychological benefit translates to more consistent exercise habits and better long-term health outcomes.
How to Choose the Right Sports Bra Style
Based on your sports bra size calculation and activity level, consider these style recommendations:
Encapsulation Bras: Ideal for larger cup sizes (C+), these bras separate and support each breast individually. Perfect for high-impact activities where minimal movement is crucial.
Compression Bras: Best for smaller busts (A-B cups), these bras press breasts against the chest wall. Excellent for low to medium impact activities.
Hybrid/Combination Bras: Featuring both encapsulation and compression elements, these offer maximum support for all bust sizes during intense workouts.
Sports Bra Materials and Health Considerations
Modern sports bra technology has evolved significantly, with moisture-wicking fabrics, antibacterial treatments, and strategic ventilation becoming standard. Look for bras with:
- Breathable Mesh Panels for temperature regulation
- Wide, Padded Straps to distribute weight and prevent shoulder digging
- Racerback Designs for increased range of motion
- Front Closures for easy adjustment and removal
When to Replace Your Sports Bra
Most quality sports bras maintain their support for 6-12 months with regular use. Signs you need a new sports bra include:
- Straps losing elasticity
- Band riding up in back
- Visible stretching or fabric deterioration
- Reduced support during movement
- Increased discomfort during or after exercise
Technical Details: Sports Bra Size Calculator
Calculation Methodology
Our sports bra size calculator uses the following professional fitting standards:
Band Size Calculation:
- Underbust measurement rounded to nearest even number
- Adjustments made for stretch and comfort factors
- Range: 28-46 inches (71-117 cm)
Cup Size Determination:
- AA: 0-1 inch (0-2.5 cm) difference
- A: 1-2 inches (2.5-5 cm) difference
- B: 2-3 inches (5-7.5 cm) difference
- C: 3-4 inches (7.5-10 cm) difference
- D: 4-5 inches (10-12.5 cm) difference
- DD/E: 5-6 inches (12.5-15 cm) difference
- DDD/F: 6-7 inches (15-17.5 cm) difference
- G: 7-8 inches (17.5-20 cm) difference
Support Level Recommendations are based on activity impact classification from the American Council on Exercise and breast biomechanics research from the University of Portsmouth’s Research Group in Breast Health.
FAQs: Sports Bra Size Calculator
How often should I remeasure for sports bras?
We recommend using our sports bra size calculator every 6-12 months or after significant weight changes (±5-7 pounds), pregnancy, or breastfeeding. Hormonal fluctuations can also affect breast size.
Can I use my regular bra size for sports bras?
Not necessarily. Sports bra sizing often differs from everyday bras due to different support requirements and compression needs. Always use a dedicated sports bra calculator for athletic wear.
What’s the difference between sister sizes?
Sister sizes are alternative sizes with similar cup volumes. If your calculated size isn’t available, sister sizes provide fitting alternatives while maintaining similar support characteristics.
How tight should a sports bra feel?
A properly fitted athletic bra should feel snug but not restrictive. You should be able to breathe comfortably while experiencing minimal breast movement during your intended activities.
Do sports bras stretch out over time?
Yes, like all elastic garments, sports bras lose elasticity with wear and washing. Most quality sports bras maintain optimal support for 6-12 months with regular use.
Can wearing the wrong size sports bra cause health issues?
Yes, ill-fitting sports bras can lead to chafing, shoulder grooves, back pain, and potentially long-term breast tissue damage from inadequate support during high-impact activities.
How do I know if my sports bra fits correctly?
The band should sit parallel to the floor, straps shouldn’t dig in, and there should be minimal breast movement during activity. No skin should spill out at the sides, top, or bottom.
Are there specific sports bras for different activities?
Absolutely. Our sports bra calculator considers your primary activities because support needs vary significantly between yoga, running, cycling, and other sports.
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