So you want to buy him a good bathrobe because the one he has now has seen it’s best days, and he is kind of embarrassing himself and you with wearing that old hotel robe with holes in it. So you want to make a good choice when you search robes for men, and you go online looking to find a quality garment that will fit him and be comfortable.
The best way to make certain that the size will be good is to measure his old robe, and if the sleeves, length and the waist were all good, then you would want to choose the same size, which does not necessarily mean the a Large for example from one retailer is the same size as the Large from another. But, no worries, the idea of a bathrobe is that it is not necessary to make a perfect fit like a shirt or pants, a loose bathrobe is preferable to one that is too small, and robes by design have waistline wrap around to accommodate his increasing girth. The choice is fairly narrow in terms of fabric, you know you want cotton terry, the most popular choice, as it can satisfy the needs of someone that puts it on right out of the shower, or over top of other clothes like pajamas.
You can consider roll up sleeves, shawl collar or kimono which has no collar, body length can run from above the ankles to kneecap, and if he is going to wear it outside at the pool or hot tub, you may want to consider a darker color that will not display soiling or stains. When men are in their robes, it is a holiday from the cares of the world, a time to be relaxing and doing nothing, and enjoying it, so pay attention to the retailers that offer a large choice of the features just mentioned, because bathrobes tend to be boring for most people, but if you expend a little effort in getting something special, he will feel like a king.