They measured my head and normally I'm a size 57. But I ride with my hair inside the helmet so the let me try 58 and 59 but both were hurting me with my hair inside. So I wanted to try size 60 but that one they have to order because they are not manh people that have that big of a headsize. And other stores don't have a size 60 either to try on so I'm a bit stuck. I really love the look of the helmet but I'm afraid to order it because I never tried the size 60.
If your helmet is fitted properly it shouldn't really give you a headache, it should be snug but not too painful. I recommend going to the store and trying them on and leaving them on your head while you shop around so you get the full feeling of it.