I have a large head and to make matters worse, very thick hair, and this hat fits.  I like that you can squash it and it pops back into place. Also since it is not real straw, you can clean it too (however, I bought mixed camel color which is hard to get dirty) It was hard to find a reasonably priced packable hat that does not look dorky. A friend recommended this brand, and I am glad she did.