I'm usually a medium in... well, almost every other Allegra K top that I own (and I own like ~10). I bought a Large because I saw some reviews about the fit being snugger than pictured, and... yep. Even the Large is almost too snug for me! I'd size up two from your usual size if you want the fit like the picture, one size if you want it to be really form-fitting. Since I'm looking at this for work and have a large bust, I need to return this and go up a size since once you hit a certain chest size, form-fitting tops get written off as "too sexy" even if you're completely covered up.

That said, it's good quality and construction, as usual with Allegra K, and the top is quite cute, so I will be exchanging for a larger size as I quite like the top. Just be advised that this runs much smaller than usual for the brand.