To find your bra size, measure your band (snugly under your bust) and your bust (around the fullest part), then subtract the band number from the bust number: each inch of difference is roughly one cup size. A 1-inch difference is an A cup, 2 inches a B, 3 inches a C, 4 inches a D. The whole process takes under five minutes with a soft measuring tape. Below is the full method, plus how to tell if your current bra actually fits.
How do you measure your bra size at home?
Measure your band and your bust, then subtract one from the other. You need a soft measuring tape and about five minutes.
- Band: Wrap the tape around your ribcage, directly under your bust. Keep it level and firm. Round to the nearest whole number.
- Bust: Measure around the fullest part of your bust, tape relaxed and level.
- Cup: Subtract the band measurement from the bust measurement. Each inch of difference is about one cup size.
If you're between sizes, the band should feel snug — it does about 80% of the support work.
What does each cup size difference mean?
The gap between your bust and band measurement (in inches) gives your cup size. Here's the quick reference:
- 1 inch = A cup
- 2 inches = B cup
- 3 inches = C cup
- 4 inches = D cup
- 5 inches = DD / E cup
Note that cup letters differ between UK and US systems at larger sizes, so always check the size guide on the product you're buying. See our bra size conversion chart for the full UK, US and Pakistan comparison.
How do you know if your bra doesn't fit?
The clearest sign of a bad fit is a band that rides up at the back — it means the band is too big. Other tell-tale signs:
- Band rides up at the back — band too big
- Spillage over the cups — cup too small
- Gaping, wrinkled cups — cup too big
- Straps digging in — band isn't supporting, so straps overcompensate
- Underwire poking — wrong shape or size for you
If your straps keep slipping, that's usually a band or strap-adjustment issue — see how to stop bra straps from slipping.
Which bra style should you choose for your size?
The right style depends on your bust and the outfit. As a quick guide: wireless for everyday comfort, push-up or convertible for shape and versatility, front-clasp for easy wear.
- Everyday comfort: a soft wireless bra like the Blossom Beauty
- Shape and lift: a convertible push-up like the Radiant Allure
- Easy on, easy off: a front-clasp style like the Opulent Allure
If you have a fuller bust, see best bras for a bigger bust; for a smaller bust, see best bras for a smaller bust. Browse the full bras collection.
How often should you re-measure your bra size?
Re-measure every 6 to 12 months, or any time your weight changes or your bras stop feeling right. Your size isn't fixed, and a stretched-out band can change your fit even if your body hasn't. See how often to replace your bras and underwear.
Frequently asked questions
Can I measure my bra size without a measuring tape?
Yes. Use a piece of string to wrap around your band and bust, mark the length, then measure the string against a ruler. The same band-and-bust method applies.
Should I measure my band snug or loose?
Snug. The band provides most of your bra's support, so it should sit firmly and level around your ribcage without digging in.
Why does my bra size feel different between brands?
Sizing varies between UK and US systems and between brands' cuts. Always measure yourself and check the specific product's size guide rather than assuming your usual letter.
Does Erblis deliver bras in Karachi?
Yes. Erblis offers free delivery across Karachi with Cash on Delivery, so you only pay when your order arrives. Every order also includes a free Erblis tote bag.
Ready to find your perfect fit? Explore the Erblis bras collection — free Karachi delivery, Cash on Delivery, and a free tote bag with every order. Use code WELCOME10 for 10% off your first order.