Is it a good idea to get a one size larger for the Helmet just incase I measured my head wrong?

It says 22 on my measurement, 22 exactly, that's SM, but I want to try getting MD incase it was just a but abit, especially since SM was 21 5/8 to 22 (I got 22 which was literally at the end). I would hate to get a size smaller, so I'm thinking about MD just incase. Do you think it's a good idea to get a 1 size larger than whatever measurement you got? Would that make a big difference if my size was for SM instead? Just wondering, I'm trying to get a Helmet soon.