I range from 6-12 again depending on the shop or item of clothing. I just put 10 a safe bet, just incase i'm having a puffier day lol. You can kind of look at yourself and think I look like a size XYZ you know. I'd say I look like a size 10. 10 can a lot fo the time be a bit too big on me and i've had a comment made that i'm more of an 8 but just to be safe idk. Oddly in primark alone my top size is 8 but my jeans size is 12, either it's shit labelling or i'm disproportionate
If you think your a 12 and look like one, go for it. 12 is a reliable size, you wont get those after BBW and you wont get those after super skinny minnies so there is more leway with it to not be egsactly a 12. Most men have no clue what the sizings mean visuals are best lol