I think this would fit someone with a waist between 32 and 36 inches very easily, with room to adjust on either side of that with a leather tool. There's a little staining on the light brown side of this reversible belt and the dark brown side is velour material. I actually have another one labeled 90 / 36 and I assume this is the same size. Of course the value is in the buckle--you can put it on any belt you want.
Take a minute to check out my feedback it speaks for itself. The item "Gucci Authentic Vintage Mens Leather Belt Buckle Italy Brown Leather 90 36" is in sale since Thursday, February 02, 2017. This item is in the category "Clothing, Shoes & Accessories\Men's Accessories\Belts".316" and is located in Lake Zurich, Illinois. This item can be shipped to United States, to Canada, to United Kingdom, DK, RO, SK, BG, CZ, FI, HU, LV, LT, MT, EE, to Australia, GR, PT, CY, SI, to Japan, SE, KR, ID, to Taiwan, TH, to Belgium, to France, to Hong Kong, to Ireland, to Netherlands, PL, to Spain, to Italy, to Germany, to Austria, RU, IL, to New Zealand, PH, SG, to Switzerland, NO, SA, UA, AE, QA, KW, BH, HR, MY.