Everyone in the fashion blogging community knows how impossible it is to know one's size across brands (and within brands the consistency and qc just isn't always there!). That's part of why I appreciate style bloggers and the reviews they do for the community. It can make it so much easier to take the guesswork out of which size to try on it what brand... questions like, does it run large or TTS are always tough to interpret since there is no standardized sizing.
You may have seen the New York Times article "One Size Fits Nobody: Seeking a Steady 4 or a 10" detailing this lack of standard sizing. (thanks for the link Clara!)
What I thought was especially neat in the article was the graph they made of various fashion labels/designers and their bust/waist/hip ratios for a size 8. Well, I think of myself as a size 4. But look at the variation there are among Anthropologie, J.Crew, Ann Taylor Loft, Anna Sui, etc for a Size 4

[click on the image to download a copy of the graphical size 4 chart of the brands listed at the end of this post. Graphical size charts for sizes 0-14 are available for download at the bottom of this post]
The NY Times article mentioned there is a company that is putting full body scanners in malls, taking your body measurements, and giving you a print out of what your size will likely be for different stores/brands within the mall. Certainly, this is a useful tool to help with the variability across brands! (although not so much for variability within a brand).
Since there aren't a lot of these size scanners out there, I thought I'd compile a few size charts for y'all of some of the brands Anthropologie carries and a few other brands I like. Unfortunately, Anthro doesn't give different size guides for its in-house labels (although we all know they seem to have very different sizing standards). If you know of any size charts for brands that could be added here, let me know (send me a note: lorispeak [at] live [dot] com). Hopefully this could be helpful to some of you out there.
To use the size charts, you need to know your bust, waist, and hip measurements. Knowing these things is also super helpful if you buy clothing on ebay or from fellow JCAs or the EA Trade Market. Most sellers are quite accommodating when asked to provide these measurements.
If you don't have a tape measure, use a string to get your measurements and then use a ruler to measure the length of the string. See instructions on how and where to take your bust, waist, and hip measurements here.
You can download a copy of a compilation of these various brands' size charts here:

Since I already had the data compiled, I thought it might be nice for some people to look up their size according to their size of one of their body parts. For instance, I know that I have large hips, and they're often the limiting factor for skirts. So I could use just my hip measurement to see what size I am across the brands. Analogously, my cousin often has to buy dresses that can accommodate her larger chest size, so using the size chart by bust size may be more helpful for her.
note: for the only following three size charts, half inch measurements were rounded down. so if a brand's size 0 fits up to a 35.5" hip, I put size 0 under 35"



Graphical Size Charts








Brands listed: Anthropologie (general), Leifsdottir, Anna Sui, Eva Franco, Tracy Reese, Corey Lynn Calter, Ella Moss, Nanette Lepore, Twinkle by Wenlan, J.Crew, Ann Taylor Loft