This is a size Men's Medium. These sweaters (not this one, but all in the line) TYPICALLY run a little small. So, when folks buy them from us, enough have remarked that they run a tad small. So, if you're a Medium, but headed towards Large, this MIGHT be too small. This should fit for someone on the smaller side of Medium, or someone who is a traditional Small. Or, if you like them form-fitting, then this Medium will work.