If you have boobs, chances are you wear a bra and have been doing so since you were whisked into the Intimate Apparel section as a gangly pre-teen. Maybe you don’t, which is also cool. But for those who do, I’d hedge a bet that you haven’t really given much thought to the size of your bra since sometime in the mid 2000’s.

Generally we just throw those babies on, and as long as they hoist our girls up somewhat, we roll on with our day. It’s rare for us to think – does this bra actually fit me correctly? Is it even doing it’s protective job here?

Well, you should think about it. As someone who was professionally trained back in 2005 as a bra fitter for my job in the Intimate Apparel department, I have seen MANY women wearing bras completely wrong for their boob/back size. One of my mates told me the other day she went to get fitted for the first time in years, and she’s TWO CUP SIZES BIGGER THAN SHE THOUGHT.

The best solution is to hightail it into your local lingerie shop or department store intimates section and have someone go at your ta-ta’s with a tape measure. But if you wanna suss if the current stuff you own is not up to scratch, here’s a basic guide.

YOU HAVE FOUR BOOBS

If your tits overflow out of your cup, the cups are too small. Here’s a fun fact I learnt back in the day – if you go down or up a back size, you have to adjust your cup size. For example, I lost some weight and went from being a 12DD to a 10E. If I had tried a 10DD, I’d have four-boob. Basically, if you go up a back size, go down a cup size. Go down a back size? Then it’s up a cup size, babey!

Triumph Beauty-Full Sunset Wired Bra, Sizes 10-16, D-E, $59.95

YOU HAVE EXTRA ROOM FOR BOOB THAT ISN’T THERE

On the flip side, if you have room in the cup for some more boob that isn’t present, your cup is – surprise, surprise – too big. This is obvious with solid cups, but for unlined bras it can be trickier to tell. An unlined bra should basically, unless designed with darts in there, flatten the nips down. Like, no sagging or bagginess.

Simone Perele Delice Full Cup Bra, Sizes 10-18, B-D, $99.95

YOUR BACK STRAP IS UP NEAR YOUR NECK

This means your back size is too big. Or, you have been a stupidhead (love you still) and were wearing it too loose. The strap should sit level across your mid-back. Matt, my beloved colleague who knows literally nothing about backs or bras, just said “mid-spine is the term” when I asked what the middle of your back is called. No Matt. Anyway, sometimes it’s because your straps are too tight (see below) so try loosening them – if it’s too big, it’ll still ride up.

Bras N Things Dentele Plunge Double Push Up Bra, Sizes 10-14, A-DD, $49.99

YOUR BACK STRAP IS SUFFOCATING YOU

Another thing that can happen – your back strap is too small. If it’s too small, it’ll feel like it’s trying to murder you. Also, you’ll get back rolls that form around it. Now, many bra fitters will tell you to buy your bra where it fits comfortably (you can fit two fingers under the band at the back) on the MIDDLE hooks. No! I disagree! Bra straps stretch over time, so I find a comfy fit on the BIGGEST set of hooks (the ones at the very end) means my back strap doesn’t get too loose too quickly. That was not part of my official training, but clearly I am extremely trustworthy and know everything. Stop questioning me.

Heidi Klum Intimates Delilah Long Line Bra, Sizes 10-14, A-E, $79.95

YOU’RE GETTING RED WELTS ON YOUR SHOULDERS

Are you copping red SORES on your shoulders at the end of the day? Your straps are too tight, my friend! You know what is wild to me, how many people don’t know that you need to adjust the bra straps of your bra. People just don’t know that! WILD. Anyway, do that. The straps should be firm enough that they stay on easily and don’t slide off your shoulders, but not cause welts.

Triumph Embroidered Minimiser Bra, Sizes 10-22, D-G, $59.95

YOU’RE JIGGLING ALL OVER THE JOINT

This isn’t one I was taught at bra school, but one I learnt from my own experience – you shouldn’t be jiggling everywhere when wearing your bra. A bit of movement is, of course, fine – they’re boobs. They’re fleshy growths on your chest, if yours are big like mine then chances are you cannot control those puppies entirely, unless in a v aggro sports bra.

But your everyday bras should contain your boobs for the most part when walking and moving around. I’ve found I need to buy minimiser bras or full cup to really get my gals on lock – half-cup and anything flimsy is bedroom-only.

Image: Hedi Klum Intimates