How To Measure Your Bra Size: Your Bra Fit Guide

How To Find Your Bra Size

Finding the right women’s bra size can seem tricky. The truth is, there’s no magical formula that will give you an exact answer as everyone’s body is different, but we do have a process for finding your starting size to make bra fitting faster and easier. Get your soft measuring tape ready and follow the below simple steps to find your size at home, making it easier to choose when you pop in store. Or skip the queues and try on in the comfort of your own bedroom by ordering on Click + Collect.

How to measure your bust size:

Your bust size is a measurement around the fullest point of your bust and will be the first step to understanding the volume of your cups. Everything we measure for bras is in inches, so ensure your measuring tape has this scale or get ready with your conversions.

• Stand in front of your mirror with a soft measuring tape, wearing either a non-padded bra that doesn’t constrict your chest or no bra at all.

• Wrap the measuring tape around the fullest point of your bust, ensuring it is straight around, parallel to the floor.

• Ensure the tape is snug, but not pulled tight or digging in, and note the number on the tape.

• Round this measurement to the nearest whole number and take note of it!

How to measure your bra band size:

Your band size relates directly to the underband of your bra — this is the number part of a bra size, usually ranging from 28 to 42, using even numbers. It is the circumference of your ribcage in inches, so you can use the same method for measuring as before.

• Stand in front of your mirror with a soft measuring tape, ideally wearing no bra at all or a non-wired bra.

• Wrap the measuring tape around your ribcage at the level where your breast meets your ribs, parallel to the floor.

• Note the number, rounding it to the nearest whole number. If it is an odd number round it up to the nearest even number — voila, that’s your bra band size!

How to find your cup size:

So, now that you have these two measurements, there is some simple maths to calculate your approximate cup size. Simply subtract your band size from your bust size. The difference between the two in inches is your cup size. The cup size of a bra is the part represented by a letter, usually anywhere from AA to G in most ranges. Each inch of difference between your measurements correlates to a cup size, as below.

Cup Size Measurement Chart

0 inches – AA

1 inch – A

2 inches – B

3 inches – C

4 inches – D

5 inches – DD

6 inches – E

This continues in one-inch increments for all other cup sizes. For example, if your bust is 35 inches and your band size is 32 inches, you have a three-inch difference, meaning you’re a cup size C. Your bra size then would be the combination of your band measurement and your cup size. So, in the above case, the cup size is C and the band size is 32, making that person a 32C. Simple!

If you’ve worked out your bra size from the above, it may seem like that’s the end of the matter, but it’s important that you know how to correctly fit a bra, as this guideline size isn’t always 100% accurate. The reason fitting a bra is so important is because the above measurements don’t account for how breast tissue is distributed on each person’s body or the shape of your breasts. We also must round the above figures to their nearest whole numbers which reduces accuracy. Some other things that may impact your bra size are the styles you choose, the materials the bra is made with (some may be stretchier than others), and even the brand you are buying your bra from, as there can be slight differences in the way the bras are sized between companies. We always recommend trying on and testing the fit of each bra you buy to ensure you’re always comfortable and correctly supported. It’s worth the extra time to get the most out of your bras!

How To Make Sure Your Bra Size Is Correct

The first step to ensuring your bra fits correctly is making sure that it is on properly. When putting on a bra, follow the below steps to ensure everything is in its place to get a more accurate understanding of your fit. This is how you should put your bra on every day, not just ahead of bra fittings!

• Fasten the bra at the rear on the loosest hooks – bras lose elasticity over time, so you need the tighter hooks to be able to keep it snug and ensure it lasts longer.

• Pull up your straps, ensuring they are sat parallel from each other, adjusting the tightness as needed.

• Lean forward to allow your breast tissue to sit fully in the cups, scooping from either side so that no tissue is being pushed under your arms.

• Pull your underwires into place, ensuring that no breast tissue is between your underwire and your ribs, and that your underwire is sat at the point where your breast meets your ribcage.

Once you are sure the bra is on correctly, we recommend checking the fit in this order to identify any issues.

• Start with your straps – check they are comfortable, and you can fit two fingers between the strap and your skin easily, but not loose enough that you can fit more.

• Pull at the back of your underband with your thumb – it should pull away from the skin, but not feel slack or loose.

• Look at the cups – they should sit flat against your breast tissue with no bulging, gaping, or dimpling. All breast tissue should be inside of the cups with no visible spillage around the cups or behind the wires.

• Check the wires – underwires should sit completely flat against your ribcage with no gaping at the centre or sides and shouldn’t be digging in or sitting on top of breast tissue.

4 Ways To Identify Badly Fitting Bras

It’s easiest to see when there is something wrong with a bra and tackle those issues to find the perfect fit. The tell-tale signs that a bra isn’t fitting right are:

• Bra straps hurt shoulders or keep falling down

If your bra straps are too tight, they can cause discomfort from pulling the cups too tight on chest as well as restricting your shoulders and back. Adjust the straps so they fit without causing red marks, but not loose enough that they fall down your shoulder.

• Bra riding up back or pinching skin

If the bra band is too loose it will ride up at the back where it is not correctly anchoring the bra in place. This can cause spillage, might require you tightening your straps, and can even cause back aches as your bust is not being supported correctly. The solution: reduce your band size.

So, how tight should bra bands be? Tight bands can cause skin chafing and tightness on your chest and back. It’s important that it is firm but comfortable. If you feel restricted uncomfortably by your underband, go up a size.

• Bra side spillage or gaps

How should a bra cup fit? Your breasts should fit snugly into the cups without squashing your skin or leaving red marks, with the cups sitting flat and no visible dimpling in the material.

If you’re finding that your breast tissue is spilling at the top or sides of your cups or underwires are sitting on top of breast tissue, it’s likely that the cup is too small and you should size up. If your cup is gaping at the top and side of your bra or the material is wrinkling, your cup may be too large and you should size down.

• Underwire bra hurts or wires sit away from the body

Underwires, while structured, are not supposed to be uncomfortable and are supposed to sit directly on your ribcage. If you are finding that your underwires are digging uncomfortably into your underarms, you may need to try a smaller cup size. If your underwires are digging into your breast tissue, you may need a bigger cup size. If your underwires are not sitting flat to your sternum and are hanging away from the body, you need a larger cup size.

Here’s our handy video explaining how to measure your bra size:

What Is A Sister Bra Size?

Sister sizes are two different bra sizes that have the same cup capacity, but a different band size. This is essential to know when adjusting your bra size during a fitting to save you time in getting the best possible fit. If you change your band size, you need to adjust the cup size too, so that it still fits correctly. For example, if you need to go down in your band size, to accommodate this change, you’d go up in your cup size.

Sister sizing examples would be:

• 32C becomes a 34B if you increase the band size or a 30D if you decrease the band size.

• 36F becomes a 34G if you decrease the band size or a 38E if you decrease the band size.

Maternity Bra Size Guide

Maternity and nursing bras fit ever so slightly differently to your regular bra — and for good reason as your body will change a lot in this time! When you’re looking for the perfect fit for a maternity bra, here are the things to keep in mind:

Wires

• It isn’t recommended that you wear underwired bras later in pregnancy so, if you’re looking at a nursing bra with underwires, we recommend speaking to your doctor or waiting until after birth to begin wearing it.

Straps

• Maternity bras feature wide and comfortable straps for additional support. If the straps feature clips, it is a nursing bra, designed for ease when breastfeeding. Ensure you know which you’re looking for as not all maternity styles are nursing bras.

Cup Size

• During your pregnancy and after birth, your cup size is likely to increase and fluctuate. We recommend buying your nursing bra with extra room to accommodate this change, either by going up a cup size or testing that you can fit your hand comfortably into the cup when it is on your body.

Band size

• Most maternity bras will come with extra hook-and-eye loops to ensure you can adjust the bra more effectively as your underband size expands during pregnancy and then reduces after birth. If you’ll be wearing the bra throughout pregnancy, we recommend fitting it on the middle hook for adjustability in both directions or, if you’re buying it for nursing, we recommend fitting it to the loosest hook.

Post-Surgery Bra Size Guide

The best post-surgery bras are designed to provide support and comfort to those who have recently undergone surgery. They differ from regular bras in that they have a front fastening, wider straps, more coverage, pockets for prosthesis and softer fabrics to be gentle on delicate skin. If you are measuring your post-surgical bra before your operation, we recommend you buy a bra 1-2 bra band sizes larger than you normally would to accommodate for potential post-surgical swelling.

FAQs

Why does my bra strap keep falling down?

• If your bra strap falls, this could be due to the strap tightness or the bra style. Bra straps should fit comfortably on your shoulder without leaving red marks or slipping down your shoulder and may need tightening to prevent this. However, falling bra straps may also mean you have sloping shoulders, so pick bras with wide straps or with a racer back that holds the straps firmly in place, and avoid styles, like balcony bras, which have wider set straps.

How to know if a bra fits?

• A well-fitting bra is comfortable and offers support without chafing, squashing your skin, leaving red marks, causing spillage or back pain. The bra band should fit flush to your skin and never ride up your back. Your bust should fit snug against the cup and underwired bras should not dig into your skin or poke your underarms, sitting flat against your ribs.

How to fix gaping cups?

• If your bra is causing gaping at the top or sides, you might be wearing the wrong cup size. First, try and tighten the bra straps, but ensure the bra band remains straight across your back. If the band rides up or if you’re still getting gaps, we recommend going down a cup size.

Why do my boobs come out of the bottom of my bra?

• If your breast tissue is spilling below your underwires or the bottom of the bra, it is likely that your underband is too loose and you may need to size down to avoid it riding up over breast tissue. If you reduce the underband size and your underwires still sit on the breast tissue, you may need to wear a larger cup size.

Why is my bra riding up my back?

• If your bra is riding up your back, it’s likely that your underband is too loose. We recommend sizing down in your underband and ensuring that straps aren’t too tight and causing it to lift.

Why does the underwire in my bra hurt?

• If your underwire hurts it may be that you are wearing the wrong bra size or a style that isn’t comfortable for your body. Try adjusting your cup size and band size until the fit feels right and, if you’re finding that underwires dig into the centre of your chest or under your arms, try a style with a smaller wire like a plunge bra.

Why doesn’t the centre of my bra lay flat against my chest?

• If the centre of your bra isn’t sitting flat, it’s likely that your bra cups are too small. We recommend trying a larger cup size and ensuring that the underband is secure to avoid it being pulled away from your ribs.

Why does my bra ride up when I lift my arms?

• A bra riding up and not staying in place is a sign that your underband is too loose. Try sizing down on your underband to ensure it can properly hold the bra in place against your body. It’s also worth checking that your straps aren’t too tight.

Why do my bra cups wrinkle?

• Wrinkled cups are a sign that your breast tissue isn’t completely filling your cup as it may be too large, we recommend trying a smaller cup size to ensure that the cup sits flush against your breasts without extra room.