Complete Bra Size & Fitting Guide: How to Measure at Home

Finding a bra that fits perfectly can feel like finding a needle in a haystack. But it’s not just about comfort—a good bra supports your breast tissue, improves your posture, and can even make your clothes look better.

If you find yourself constantly adjusting straps, pulling at the band, or dealing with wires digging in, you are likely among the 80% of women wearing the wrong size.

This guide will help you measure yourself at home and find your true fit.

#Signs You’re Wearing the Wrong Size

Before you measure, check for these red flags:

• The Band Rides Up: The back band should be level with the front. If it arches up, it’s too big.
• Straps Dig In: The support should come from the band, not the straps. If your shoulders have grooves, your band is likely too loose.
• Quad-Boob: If your breasts spill over the top of the cups, the cup size is too small.
• Gaping Cups: If there’s space between your breast and the cup, it’s too big or the wrong style.
• Floating Gore: The center piece (gore) should sit flat against your sternum. If it floats, the cup is too small.

#How to Measure Your Bra Size at Home

You’ll need a soft measuring tape and a non-padded bra (or go braless if comfortable).

#Step 1: Measure Your Band Size

1. Wrap the tape measure around your ribcage, directly under your bust.
2. Make sure the tape is parallel to the ground and snug (exhale to get the smallest measurement).
3. Round to the nearest whole number.
   • If the number is even: Add 4 inches.
   • If the number is odd: Add 5 inches.
   • Example: Ribcage is 29 inches (odd) + 5 = 34 Band.

#Step 2: Measure Your Bust Size

1. Wrap the tape around the fullest part of your bust (usually across the nipples).
2. Keep the tape loose enough to breathe but not sagging.
3. Round to the nearest whole number.
   • Example: Bust is 36 inches.

#Step 3: Calculate Cup Size

Subtract your Band Size (Step 1) from your Bust Size (Step 2). The difference in inches corresponds to your cup letter.

• 0 inch = AA
• 1 inch = A
• 2 inches = B
• 3 inches = C
• 4 inches = D
• 5 inches = DD / E
• 6 inches = F
• …and so on.

Example Calculation:

• Band: 34
• Bust: 36
• Difference: 2 inches = B Cup
• Final Size: 34B

#Understanding “Sister Sizes”

Sometimes your calculated size still doesn’t feel right. This is where Sister Sizing comes in. Sister sizes are bras with the same cup volume but different band sizes.

• If the band is too tight: Go UP a band size, and DOWN a cup size.
  • 34B -> 36A
• If the band is too loose: Go DOWN a band size, and UP a cup size.
  • 34B -> 32C

#Tips for the Perfect Fit

1. Scoop and Swoop: When putting on a bra, lean forward and scoop all your breast tissue from the underarm into the cup. This ensures the wire sits on your ribs, not your breast tissue.
2. Fasten on the Loosest Hook: A new bra should fit snugly on the loosest hook. As the elastic stretches over time, you can move to the tighter hooks.
3. Check Every 6 Months: Weight fluctuations, hormonal changes, and age can all change your size.

#Conclusion

Don’t settle for discomfort. Taking five minutes to measure yourself can change your daily life. Remember, these numbers are just a starting point—try on different styles to see what works best for your unique shape!

[!TIP] > Next Step: Learn about the anatomy you’re supporting in our Applied Anatomy of the Breast Guide.

Return to the main guide: Breast Care Tips