YOU PROBABLY CAN’T wait to get yours off at the end of the day, but there’s lots you don’t know about the humble bra.

Here’s ten essential facts about over the shoulder boulder holders.

1. Firstly, do women really even need bras?

A French ‘study’ done by Jean-Denis Rouillon in 2013 suggests that your breasts will sag the same whether you wear a bra or not.

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However, after some sceptism from experts, Rouillon backtracked on his claims, saying his results were “preliminary” and “unpublished”. So keep your bras on, ladies.

2. How do you know if you’re wearing the right size?

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Ladies are always being told that they’re doing bras all wrong, so here’s how you know if it fits:

• The cups should be smooth and unwrinkled – your breasts shouldn’t spill out over the top, nor should there be a gaping space between your bra and your boob;
• The underwire should sit flat against your chest;
• The band should be straight and firm across your back- the general rule is if you can’t comfortably fit two fingers underneath the band, it’s too tight.

3. Is my back fat supposed to spill out over the band like that?

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Yeah, actually! It’s not just you. Bra fitter Kim Caldwell tells the Huffington Post:

Unless you’re an Olympic swimmer, you’re going to have it. It’s an elastic going around your body and hugging you.

Don’t let it dissuade you from buying a bra that fits properly.

Make sure the bra fastens comfortably on the first (loosest) hook when you buy it, because if you’re using the tightest one straight off, there’s nowhere to go when the bra starts stretching out.

4. Does sleeping in a bra prevent sagging?

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Some women like to keep their bras on through the night, while others have them off the minute they get in the door.

But there’s no real proof that wearing a bra 24/7 does anything but make you uncomfortable.

5. The cup is the part doing all the heavy lifting, right?

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Nope! It’s actually the band across the back that’s working to keep your boobs perky, believe it or not.

6. How long should a bra last you?

Bra experts say a good bra probably needs to be binned after six to nine months.

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So it’s definitely time to ditch that raggedy Wonderbra you bought on sale in Shaws (Almost Nationwide) in 2010.

7. How long have gals been wearing bras?

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Since the Bronze Age! Women of the Minoan civilisation from the island of Crete were depicted wearing bikini-like garments back in the 14th century. Cute.

8. How many bras does the average woman own?

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Nine. And probably wears only three of them regularly, in fairness.

9. Why do they make wearing nice clothes so difficult?

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We’ve all experienced the joy of finding a beautiful top on sale, then discovering it’s backless.

But again, it’s not just you - 27% of women have decided against buying an item of clothing because they didn’t have the right bra for it. The struggle is real.

10. The world’s most expensive bra costs WHAT?!

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A mere $10 million.

The ‘Royal Fantasy’ bra, which is encrusted with rubies, sapphires and diamonds, was worn by Candice Swanepoel during the 2013 Victoria’s Secret Fashion Show.

Doesn’t look too comfy though. We’ll pass.

More: 10 facts about boobs everyone should know>

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