Size 12 = 'x' amount of weight?

How tall are you?

Depends on your height, frame, shape, how muscular you are...

Also, it's not obvious from your profile where you are from. Different countries have different sizing systems. Eg. a 12 in the US would be bigger than a 12 in the UK.

The more muscular you are, the smaller size you are at a particular weight. Muscle is denser than fat.

You can have two women who are the same dress size, but one of them weighs 30lb more than the other. And the one who weighs 30lb more would be healthier and look better, because muscle makes women look fit and toned, it also means stronger bones.

I'm personally aiming to be as heavy as I can at a goal dress size, rather than any particular weight. When it comes to bones and muscles, heavier = healthier. When it comes to body fat of course heavier = more of it = not so healthy. You have to balance out the two things. I'm aiming for stronger, heavier bones and muscles and body fat at the low end of the healthy range. I'm expecting my weight to be in the heavy end of BMI by the time I get there, but I'm less bothered about weight, more bothered about being strong, fit and having a low (but still in the healthy range) body fat percentage.

I'm 5' 5" and 164 and can get into some 10's but usually wear a 12. I could probably get into a 12 around 170.

I'd say it depends on how tall you are and how you are built. I'm 5'9 with an athletic build (little difference between my waist and hips with full thighs) and I fit a 12.

I'm 5'3" and weigh 160 pounds. I wear a US size 10 pants - sometimes an 8, depending on the cut. My dress size is pretty much a solid 10. I wear M or L shirts, again, depending on the cut.

As everyone else has said - it really depends on your body type. I am short, but have a medium/large frame and have a good amount of muscle.

I'm 5'5" and just started fitting into a size 12, at 192. But I've always weighed more than I look too. My sister, who is 5'6" and 160-165, also wears a 12.

I am in a size 12. Height: 5'9", weight: 174 with an hour glass shape.

Depends how tall you are and how muscular i suppose. I weigh 156lb at the moment and am a size 10 uk

Im 5ft 6

I'm 5'7", and about 150-160 is a size 12 for me. I'm also majorly pear shaped.

This. It depends on the cut and how you carry the weight though. I just picked up a pair of BDU pants in a size 14. I tried the 12 but they did that weird pulling thing across the tummy/crotch.

I'm a 12 when I'm in the 148 - 155 range. Anything above that is questionable.
I'm a 10 when I'm 138, because I carry it in my hips and thighs.

If you're an apple and carry weight on the top half, you might be a smaller pant size at the same weight as someone who's a pear.

Just out of curiosity (I'm a man)...is there a reason that the clothes sizing system for women is this way (meaning arbitrary numbers instead of inches)?

What is it based on?

I am 5'8" and I was a 12 somewhere in the 16-165 range, I think. I am 150 right now and am between an 8-10

I'm 5'9 and about to drop into a size 12 and I weigh 188. So it's really hard to say...

Won't give you an exact number, but may give you an idea. I used it when I first started to get a general idea of where I want to be

http://www.mybodygallery.com/

It depends on so much! I'm 5'8" and 196lbs and I currently wear a size 14. I should be in 12 by 180-185. I'm a muscular build, though.

It is a learning process and your goal weight will likely change as you progress, especially if your goal is a size and not necessarily a number. My goal is 175 pounds now, but it might change as my goal is trim, fit and healthy and to fit back into my prepregnancy size 10-12s.