I'm a college student and only bought these for use as shoes from my dorm room to the floor's bathroom. For that purpose, they're a 5/5. However, they're not that comfortable. They have this arch support deal which is really just a hardish elevation coming where your arch should be. It's not comfortable, but I've never had arch issues. Maybe if you do, this'll work for you.

They look like they'll last longer than 10 dollar Walmart sandals so that's a plus.

As far as sizing goes, if you have long toes order a size up. These fit almost exactly your foot size, it's not like cheaper flip flops that are around the size of the insole of other shoes. So if you have long toes your toes might end up getting close or hanging over the edge (especially your big toe). Just make that judgment for yourself and size up if needed. I usually wear a 9-9.5 in Nike shoes and a 9 barely fits in this. (My big toe is centimeters from hanging over the edge).

If you're going to be wearing these all day, I don't recommend them. Go ahead and spend the extra 40 dollars and get yourself a better pair of reefs. If you just go to the beach once in a while or just need basic flip flops, these work well.