Although our breasts as women fluctuate up to six times in our life - not to mention the variations depending on where you shop - most of us probably kept abreast (sorry) of our band measurement and cup size.
But this may no longer be enough.
Breasts come in all shapes and sizes - and aren't always as uniform a certain magazines and the advertising industry would have us believe.
There are seven very different types of breast, and according to Glamour and research done by lingerie experts ThirdLove, there's a corresponding bar for each.
So familiarise yourself below with your breast type below and dress your ladies accordingly - they'll thank you for it.
And if you're not sure if you're wearing the wrong bra size, take our quick quiz at the bottom.
1. Asymmetric
Do I have them?
Probably! Much like we all have one foot larger than the other, most women have one breast larger than its mate.
But sometimes this difference is noticeable, and can even cause discomfort, so read on if that applies to you.
What do I need?
A bra with removable inserts / padding means you can address any difference in size by removing the padding on your larger side.
2. East West
Do I have them?
Yes - if you find your breasts point out away from your torso and there's a noticeable gap between the two.
What do I need?
For East West ladies, a t-shirt bra is best, as this will push your breasts in slightly, giving you an even outline.
3. Side set
Do I have them?
Yes, if like East Westers your breast naturally fall away from the centre of your torso BUT - crucial difference - are a fuller.
What do I need?
You need something a little more dramatic than a t-shirt bra. Instead, try a plunge bra which will help pull your breasts both up and in.
Try a larger cup size than normal, as you may find you spill out of the side slightly.
4. Slender
Do I have them?
If your breasts sit on the smaller end of the scale, are longer than they are wide BUT are wider at the top than they are the bottom (still with us?) then - yes!
What do I need?
Give a plunge bra a go as this will lift and centre your breasts. If it suits your body shape and you feel like it, a bra with padding on the outer curve will provide a bit more drama.
5. Bell shape
Do I have them?
Yes, if you find your breasts are narrower at the top than the bottom, and fuller at the bottom than they are at the top.
What do I need?
Ladies with bell shapes need a fair amount of coverage and lift, as they tend to be more buxom than their Slender sisters.
Pretty as they may be, try to avoid balconette bras.
6. Tear drop
Do I have them?
These are considered the 'quintessential' type of breast. Typically, they are fuller at the bottom than at the top, but to the same extent that Bell shapes are.
What do I need?
Lucky old you - not much! Your breasts will work with any type or style of bra so have some fun with your lingerie!
7. Round
It's a word which may you automatically associate with breasts, but some are in fact rounder than others.
Do I have them?
Yes, if your breasts are as equally full on the top as they are on the bottom then they're round.
What do I need?
As far as these things go, you're lucky. Due to your shape, you don't need much in the way of support and can get away without underwiring and too much of a structured cup.