I haven't tried it on, but the tag says Large, and if I hold it up to myself I can tell it would fit loosely. I'm usually a medium/large. But the material is not stretchy, so if you are on the high end of a large I can imagine it being snug. Hope that helps.
My house is a non-smoking home, yes. But these clothes are from a storage locker, so I can't say where they've been before now. Shoulder to shoulder looks to be approx 15 inches, shoulder to bottom hem approx 23 inches.