I wear a 34 to 36 depending on maker of pants, I ordered a 38 for the belt. I've found that you need to order at least 2 sizes up on belts and this holds holds true here. The belt sports 5 holes about 1 1/2 " apart with room to add if needed. Yes you can change the buckle although this one is rather nice as is. Hope this helps... great belt... everyone's told me time and time again!!!