US/Canada Bra Size Calculator

Wearing the right bra size isn’t just about comfort—it’s about confidence, posture, and long-term health. Shockingly, studies suggest that 80% of women wear the wrong bra size, leading to issues like back pain, skin irritation, and poor support. Whether your straps dig into your shoulders, your band rides up, or your cups gap, an ill-fitting bra can ruin your day. But finding your perfect size doesn’t have to involve awkward fittings or guesswork.

Our Bra Size Calculator (USA & Canada) takes the stress out of bra shopping. In just three simple steps, you’ll get an accurate measurement from the comfort of your home. Plus, our Sister Size Calculator helps you find alternatives if your usual size feels off. Ready to say goodbye to discomfort?

👉 Use our free Bra Size Calculator below and discover your perfect fit!

How to Measure Your Bra Size at Home

Finding your bra size requires two key measurements: band size (underbust) and bust size (overbust). Here’s how to do it right:

1. Measure Your Band Size

• What You Need: A soft measuring tape.
• How to Do It:
  • Stand straight with your arms relaxed.
  • Wrap the tape snugly around your ribcage, just below your bust.
  • Ensure the tape is parallel to the floor and not twisted.
  • Note the measurement in inches.

Calculating Band Size:

• If the number is even (e.g., 30, 32), add 4 inches.
• If it’s odd (e.g., 31, 33), add 5 inches.
• Example: A 29-inch underbust becomes a 34-inch band (29 + 5 = 34).

2. Measure Your Bust Size

• How to Do It:
  • Wrap the tape around the fullest part of your bust (usually at nipple level).
  • Keep the tape loose enough to avoid compressing your breasts.
  • Record the measurement in inches.

3. Calculate Your Cup Size

Subtract your band size from your bust size to determine your cup:

Bust Size – Band Size	Cup Size
1 inch	A
2 inches	B
3 inches	C
4 inches	D
5 inches	DD/E
6 inches	DDD/F

Example:

• Band Size: 34 inches
• Bust Size: 37 inches
• Difference: 3 inches → C cup
• Final Size: 34C

Bra Size Chart for USA & Canada

Use this chart to cross-reference your measurements:

Band Size (inches)	Bust Size (inches)	Cup Size
30	31	30A
32	34	32B
34	37	34C
36	40	36D
38	43	38DD/E

Note: Sizes vary slightly between brands. Always check a brand’s specific sizing guide before purchasing.

Sister Size Calculator — What Is a Sister Size?

Sister sizes are bra sizes that share the same cup volume but have different band lengths. They’re lifesavers if your usual size feels too tight or loose.

How Sister Sizes Work

• Rule 1: Go down a band size → increase the cup size.
  • Example: 34C → 32D
• Rule 2: Go up a band size → decrease the cup size.
  • Example: 34C → 36B

Why Sister Sizes Matter:

• A 32D and 34C have the same cup volume but different band lengths.
• If the band feels tight but the cups fit, try a sister size with a larger band and smaller cup (e.g., 34C → 36B).

Sister Size Chart

Original Size	Sister Sizes
34C	32D, 36B
36D	34DD, 38C
30B	28C, 32A

Pro Tip: Use our Sister Size Calculator to find alternatives instantly.

Why Bra Sizes Differ in USA vs. Canada

While the USA and Canada use the same basic sizing system (band + cup), subtle differences exist:

1. Band Sizing: Both use inches, but Canadian brands may align closer to European sizing for larger cups (e.g., using E instead of DDD).
2. Cup Progression:
   • USA: A → B → C → D → DD → DDD → G
   • Canada: A → B → C → D → E → F → G

Shopping Tip: When buying from international brands, check their size conversion charts.

Common Signs You’re Wearing the Wrong Bra Size

1. Band Rides Up:
   • Cause: Too loose.
   • Fix: Try a smaller band or sister size (e.g., 36C → 34D).
2. Cup Spillage:
   • Cause: Cups are too small.
   • Fix: Size up the cup (e.g., 34D → 34DD).
3. Gaps in Cups:
   • Cause: Cups are too big.
   • Fix: Size down the cup or tighten the band (e.g., 34C → 34B).
4. Straps Digging In:
   • Cause: Band isn’t supportive enough.
   • Fix: Adjust straps or try a smaller band.

Tips for Finding the Perfect Bra Fit

1. Measure Every 6 Months: Weight fluctuations, hormones, and aging can change your size.
2. Test the Fit on the Loosest Hook: Bras stretch over time—starting loose ensures longevity.
3. Try Different Styles:
   • Balconette: Lifts and separates (great for small-to-medium busts).
   • Plunge: Ideal for low-cut tops.
   • Full-Cup: Offers maximum coverage and support (perfect for larger busts).
   • Sports Bras: Opt for encapsulation styles (not compression) for high-impact workouts.
4. Check the Gore: The center panel should lie flat against your sternum.
5. Scoop and Swoop: After putting on your bra, lean forward and adjust your breasts into the cups for full coverage.

Use Our Face Shape Calculators Today!

There’s no reason to settle for discomfort. Whether you’re a 32A or a 42G, the right bra exists—and our Bra Size Calculator will help you find it.

👉 Ready to transform your lingerie drawer?

1. Measure your band and bust.
2. Enter your numbers into the calculator.
3. Explore sister sizes for flexibility.

Say goodbye to pinching bands and slipping straps. Your perfect fit is just a click away!

Final Thoughts

A well-fitting bra isn’t a luxury—it’s a necessity. It supports your posture, enhances your silhouette, and boosts your confidence. With our easy-to-use calculator and sister size guide, you’re equipped to navigate the world of bra sizing like a pro. Remember: Your body is unique, and your bra should celebrate it. Measure, calculate, and step into comfort today.