How to Find Your Cup Size: A Step-by-Step Measurement Guide
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📏 For the full size chart, see Bra Cup Size Chart & Sister Sizes: The Complete 2026 US Sizing Guide.
Tools You'll Need
- Soft measuring tape
- Non-padded bra
- Mirror (optional)
- Size conversion chart
4-Step Cup Size Measurement Method
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Measure Band Size:
Wrap the tape snugly under your bust where the bra band sits. Round to nearest whole number (inches).
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Measure Bust Size:
Measure around the fullest part of your bust while wearing a non-padded bra. Keep tape parallel to floor.
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Calculate Cup Size:
Subtract band measurement from bust measurement. Use this difference to determine cup size:
Difference (inches) Cup Size 0-1 AA 1-2 A 2-3 B 3-4 C 4-5 D 5-6 DD/E -
Verify Fit:
Check for common signs of proper fit: no breast spillage, centered underwire, snug band.
Expert Tips for Accuracy
- ➤ Measure at same time monthly (hormonal changes affect size)
- ➤ Lean forward during bust measurement for full capture
- ➤ Check both imperial and metric measurements
Avoid These Measurement Errors
- Measuring over padded bras
- Pulling tape too tight
- Ignoring asymmetric breasts
- Using old/stretched measuring tape
Frequently Asked Questions
Q: How often should I recheck my cup size?
A: Experts recommend remeasuring every 6-12 months or after significant weight changes.
Q: Does cup size change with band size?
A: Yes - a 34C has same cup volume as 32D (sister sizes).
Find your perfect bra at Irene's Secret.
Frequently Asked Questions
How do I find my cup size?
Measure your band and bust. The difference in inches maps to your cup letter.
What size cup is 34B?
A 34B is a 34-inch band and a 36-inch bust — about a 2-inch difference.
Is 36C a big cup size?
36C is the US average. Big is relative.
How do I know if my cup is too small?
Spillage at the top, the band feeling tighter than usual, tissue pushing out from under the cup.
What is the difference between band size and cup size?
Band size is the number. Cup size is the letter. They work together.
Should I add inches to my band measurement?
No. Modern brands use your actual measurement.
How often should I re-measure?
Every 6-12 months, or after any major life change.
Use the step-by-step measuring guide.
