Bra Fitting: How to Measure Yourself

For years, I was confused about bra sizing and what it all meant. I was “fitted” at various places – all of which gave me different sizes, none of which fit well – but I still had no real idea of what the letters and numbers were for. The “36” in a 36DD probably had something to do with bust measurement, I thought, and “DD” just meant “really big boobs.” But no one ever explained it all to me, and I grew more and more frustrated with painful and ill-fitting bras. I couldn’t go above a DD, because a DDD bra would be WAY huge (if they even existed), I thought. And I had no idea why my bras felt too small yet the bands felt too big. It wasn’t until I scoured the internet for guides and for what bra sizes really meant that I was able to estimate what my bra size really was and finally find a bra that actually fit me.

There are some great guides out there already for measuring yourself for a bra size, but here’s my explanation/experience. If you’ve never been sure of what your bra size is, or you just want to check or gain some understanding about how sizing works, correctly measuring yourself is the best starting point!

What you’ll need:
-A fabric tape measure

Optional, but helpful:
-A mirror
-Someone to help you hold the tape straight

Step 1
You’ll want to be standing in front of a mirror if possible, wearing just a bra. Start by taking your underbust measurement (in inches). Hold the tape fairly firmly, but not so tight that it cuts into your skin. The number you get will be your approximate band measurement – the even number you see when you read a bra size (i.e. the “32” in a 32D bra).

Write down this measurement, rounding to the nearest even number if it’s a half number and/or an odd number. In my case, the measurement is a little under 27.5, so my band size is 28.
If you get an odd number, say 31, you’ll probably first want to try rounding up to a 32 band size, but you may need to round down to 30 if you find that a 32 band feels too big, especially if you’re slightly under a 31.

Step 2:
Next, you’ll want to take your bust measurement. There are two methods you can try.

Method A
This is probably the preferred method. For this first method, make sure you’re wearing a non-padded, non-sports bra. Hold the tape somewhat loosely, but tight enough to keep it straight across your bust. As in Step 1, a mirror and/or a friend may be helpful here to help make sure the tape is straight.

Write down this measurement. In my case, it’s about 36. Round up or down to the nearest number if you get between two numbers.

Method B
Alternatively, you can bend forward, sans bra, and take your bust measurement this way. Some people may find a more accurate measurement this way; it’s also best to do it this way if you don’t have any bras that fit (that is, if they’re squishing you down or gaping, thus not allowing for an accurate measurement).
This number may be a little different than the number you get for the first method of this step. When using this second method, I get 37.

Step 3:
Subtract the number you got from Step 1 (your underbust measurement) from Step 2 (your overbust measurement for whichever method you used) to get a cup size.

In my case, since my actual underbust measurement was closest to a 27, I’ll use this number, even though my band size is a 28 (some people use their estimated band size for this equation, but I get a more accurate estimate if I use my actual measurement):
3627= 9
3727= 10

Step 4:
Starting at the letter A=1, count up however many letters equal to the number you got. (For example, a difference of 4 would equal a D). This can get a little tricky, particularly since US and UK brands use different sizing, and because of double letters. It’s helpful (and probably necessary) to refer to a chart when figuring out cup size. (Be sure to start at A for 1 inch difference)

In my case, using the UK side of the chart:
9 = G
10 = GG
(A, B, C, D, DD, E, F, FF, G, GG = 10)

Thus, I should start by trying a 28G or 28GG (UK sizing).

If you came up with a size that you’ve never heard of, never fear! If you can’t find your true size in store, there are many great places online that stock a wide range of beautiful bras.

I know that I generally wear a 28GG (but ranging from a 30G to 26J in various brands!).
For me, then, I get the most accurate measurement when I bend forward to get my overbust size and when I round down to my actual underbust measurement for the equation rather than use the rounded-up band size.

These slight variations you can get with different numbers is why it’s very important to treat this as a mere starting point for figuring out a correct bra size. There is no “magic formula” that will give everyone their exact bra size. This is partly due to differences in body type and the need to use “rounded” measurements. In my case, I measure around 27.5 and either 36 or 37, rather than the 28 and 36 that could be used for this calculation if I rounded differently. I also have fuller-shaped breasts, which may lead to the need to go up a cup size when using these kinds of calculations. You may need to go up or down a band size depending on how firm your underbust is.

Thus, the only real method to find out your bra size is to actually try on a variety of brands and sizes of bras, keeping in mind that sizing will often differ slightly between brands and even between different styles in the same brand. What these calculations do accomplish, however, is that they give you a very good starting point for figuring out a range of sizes to try. Most certainly it is much more accurate than other methods that tell you to either add 4-5 inches to your underbust measurement or take an over-the-bust measurement to get a band size. Either of these inaccurate methods will  give you a band size that is too large and a cup size that is too small – for example, the Victoria’s Secret method of taking an over-the-bust measurement rather than an underbust measurement gives me a size 32D or 34C – sizes that are completely, ridiculously, and totally off (see my previous post on getting measured at VS).

When trying on bra sizes, remember a few key things:
-If the cup is too small, go up a cup size, not a band size.
-If the band is too big, go down a band size and up a cup size (i.e. from a 34F to a 32FF). This will keep the cup volume about the same.