How to measure your bra size at home in 4 easy steps

Never again settle for anything less than the perfect fit

Updated on 08 Feb 2023, 16:50 GMT

Orin CarlinSEO Content WriterLondon

Forget getting caught in a downpour or missing the last train, nothing has the ability to ruin your day like an ill-fitting bra. Irrespective of whether putting on your bra is as ingrained in your morning routine as cleaning your teeth, or whether you only reach for one from time to time, knowing how to measure your size – properly – is crucial.

Women's bodies fluctuate constantly, and if you get your size measured by a professional once, don't let that dictate your entire bra collection. It's well worth keeping an eye on where your body is at so that you can rest easy, secure in the knowledge that your lingerie is supporting you to the max and helping you look your best.

Bra sizing might initially feel like a minefield – with so many tips and tricks out there it can be confusing to know where to start. Luckily Lucy Litwack, CEO and owner of luxury lingerie label Coco de Mer is on hand to help you achieve the perfect fit.

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Common bra sizing mistakes

Wearing your bra on the tightest hook. "This could mean you are wearing a band size that is too big and the shape of the cup and spring of the wire will be the wrong size for you, therefore not giving you the support you need,"Lucy explains. "Ideally a bra should fit comfortably on the loosest hook and eye when first purchased and you should be able to fit two fingers under the underband with ease."

Having bra straps that are too loose or too tight. "The underband of a bra front and back should always sit parallel to the floor. If your bra is riding up at the back it not only impacts your posture but puts pressure on your shoulders."

Opting for a smaller bra to increase cleavage. "This is a big no-no and can be really damaging to your breast tissue. You can tell quite quickly if you are wearing a bra that is too small. It will feel restrictive and uncomfortable, and the front central gore of the bra (where the two wires meet in between the bust) should always sit flush to the chest bone. If the bra is creating a ridge in the top of the breast tissue, it's time to move up a cup size."

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How to measure your bra size at home

Step 1 – Band measurement

"Standing upright and braless, use a measuring tape to measure around your underbust, keeping the tape level and snug to the body," Lucy says."The tape should sit where the band of a bra would typically sit. Measuring in inches, round up to the nearest whole number and add five. If that number is even, that is your band size. If odd, round it up to the nearest inch to work out your band size."

Step 2 – Bust measurement

"There are a few methods to work out the cup size, but the easiest way is to wear an unpadded bra you own that fits comfortably in the cup. Keeping the tape level, measure around the fullest part of your chest and note down your number in inches."

Step 3 – Find the difference

"Next, subtract your band measurement from your cup measurement. The difference between the band and the cup measurement will equate to your cup size, using the following sequence: 0=AA; 1=A; 2=B; 3=C; 4=D; 5=DD; 6=F; 7=FF; 8=G; 9=GG; 10=H; 11=HH; 12=J; 13=JJ; 14=K, and so on."

Bra sizing chart

Step 4 – Amalgamate the two

"Finally, combine your band size with your cup letter to work out your bra size. While different brands, styles and fabrics will have different fits that need to be considered, this method is a great starting point if you are unsure of your size," Lucy says.

How do you know whether your bra fits properly?

A good fitting bra should neither gape, dig in, nor should the straps leave unsightly red indentations. "It will sit snug to your body without being tight and feel supportive - ultimately you will forget you are wearing it throughout the day," Lucy explains.

"Your bra should fit comfortably on the loosest hook and eye (when first purchased) and the underband should always sit parallel to the floor. Remember the two-finger rule - you should be able to fit two fingers comfortably underneath the underband and one finger under the straps at the point of the shoulder."

Spillage is also a no-no. "The breast tissue should never spill over the top of the bra or around the sides," Lucy says. "This is an indication that it is too small. You should be able to lean forwards fully and not slip out of the cup."

Which bra styles are best suited to each of the different body shapes?

Plunge bra

Plunge silhouettes are excellent for creating cleavage and lift – ideal for those with outward facing busts as the shape will bring the breasts in. "It is a great shape for anyone who struggles with the gore of their bra not sitting flush to their chest," Lucy says. "For those requiring a little extra lift, we would always recommend opting for a plunge bra with a crescent pad at the base of the cup."