I have been searching for a pair of light hiking shoes to fit in my carry on.  I had tried several, but either they didn't fit right, or were too heavy.  I had a pair of Ahnu regular shoes and decided to give these a try.  I'm glad I did.  They fit great, they are comfortable and held up as I hiked up rocky hills and walked city streets.  I wasn't sure what size to order, but I followed their directions and measured my foot, and ordered what was suggested.  They fit just fine. I'm very happy with them.