Deena tried on 4 different sized pants. Her photos prove our biggest fashion pet hate.

Here’s what I like to call a typical week as a woman:

Monday: You’re a size 10.

Tuesday: Oops, now you’re a 14!

Wednesday: Oh, look! Size 8!

Thursday: Aaaaaaaand back to 10 again.

Friday: Chuck on a size 16, lady pants.

Saturday: You fit nothing. Time to wear a moo moo gurlfriend.

Sunday: Size 12. Wait… no… 18. Wait… no…. 12. I dunno.

We all know it: women’s sizes are bloomin’ ridiculous. There is NO consistency, and the industry seems pretty hellbent on doing absolutely bloody nothing to keep it that way.

It’s infuriating, and something that youth counsellor of six years Deena Shoemaker knows all too well.

"I've listened to countless girls tell me about their new diets and weight loss fads," Deena, from Kansas in the United States, wrote in a scathing Facebook post on the weekend.

"I've had girls sob in my arms and ask me, 'if I were skinnier, would he have stayed?' I've counselled girls who were skipping meals. I've caught some throwing up everything they've just eaten.

"But as I was going through my clothes tonight I started to notice how dramatically different the size of all my pants were. And I have a real problem with the fact that my size nine pants fit me THE EXACT SAME WAY that my size 16 pants do."

The post, which includes photos of Deena wearing six different pairs of pants, has since gone viral for all the right reasons, receiving 77,000 shares.

"STOP telling my girls that a size eight is the 'ideal body size' and the 'epitome of beauty' if you're going to change a size eight into a 12 or a 16 or whatever number you feel like on any given day."

Can you hear that? That's the applause of women around the world.

"And to you, my dear beautiful girls, my size six girls or my size 22 girls, your size doesn't determine your beauty; your life does. The size printed inside your clothes is subjective to the fashion industry's personal taste and it fluctuates rapidly. Stop believing the social normatives about who and what you should be.

"You are lovely and you are loved.  Just exactly the way you are."

Bravo, Deena. Bravo.

You can read the full Facebook post from Deena below.

*Note: We've changed the US sizes in Deena's quotes to reflect Australian sizing.

Mamamia encourages anyone struggling with body image issues to call The Butterfly Foundation on 1800 334 673.