I am just putting this out there for others after having searched about the fit of a Klim helmet and not really liking what I had found. Your mileage may vary but below is my experience/opinion.
I had read several places where people said they run small and to go up one size. I have 2 different HJC helmets (closed and open) that fit good in L. I could probably jam my head into a M and have it be uncomfortable or put on an XL and have it moving all over the place, so in other words I was a solid L in HJC. Both fit good and I really like the open face HJC, but when I saw the Klim listed at Atomic Moto for $177 with free shipping I just could not help myself as I love all my Klim gear (I am now basically all Klim except mid layer depending on which one I wear and boots which will probably come along before too long). I searched and worried about size and whether or not I should order L or XL and finally ordered an L (Atomic Moto did not have anything bigger than L at that price) and received it yesterday and it seems to fit great. I noticed right away that it does sit higher on your head than HJC but the fit was good, just a little different feel. I would say unless you are right between sizes and then perhaps you would err on the larger size, but otherwise my experience would be to just order the size you wear. Everything about this helmet seems top notch as I have come to expect from Klim. The bag is awesome but for me I could really care less about having a fancy helmet bag so too bad you couldn't save another $30-35 and not get it.
I had read several places where people said they run small and to go up one size. I have 2 different HJC helmets (closed and open) that fit good in L. I could probably jam my head into a M and have it be uncomfortable or put on an XL and have it moving all over the place, so in other words I was a solid L in HJC. Both fit good and I really like the open face HJC, but when I saw the Klim listed at Atomic Moto for $177 with free shipping I just could not help myself as I love all my Klim gear (I am now basically all Klim except mid layer depending on which one I wear and boots which will probably come along before too long). I searched and worried about size and whether or not I should order L or XL and finally ordered an L (Atomic Moto did not have anything bigger than L at that price) and received it yesterday and it seems to fit great. I noticed right away that it does sit higher on your head than HJC but the fit was good, just a little different feel. I would say unless you are right between sizes and then perhaps you would err on the larger size, but otherwise my experience would be to just order the size you wear. Everything about this helmet seems top notch as I have come to expect from Klim. The bag is awesome but for me I could really care less about having a fancy helmet bag so too bad you couldn't save another $30-35 and not get it.