I normally wear a size 9.5. Since Sanuk doesn't make half sizes, and this was my first time wearing their brand, I used the Amazon reviews to help make a decision on which way to order. According to nearly everyone, these ran small so I opted to order size 10 in black. I received my order, tried them on, and was happy with the fit, but I could still tell they weren't ideal. Most notably, they felt very long when walking. That extra bit of length is a tad heavier than I'm used to in a flip-flop. My feet would slide around a little (which is expected when your shoes are too big!) but not enough to make them uncomfortable. The overall width is slightly narrow, but the straps fit well without digging in. I liked them enough not to return them, but there was always the niggling feeling that perhaps the size 9's would fit better. After wearing them around the house for a couple weeks I decided I liked them enough to purchase a second pair, so this time I ordered a size 9 in brown.

The front section of the 9's are nearly identical to the 10's.The straps felt tighter against the tops of my feet in the smaller size. It was slightly uncomfortable at first, but with a few minutes of wear this eased up quite a bit. After walking for a while, I don't even notice it. The overall width is exactly the same as the 10's, but the sizing difference is clear when it comes to the back of the sandals. In the 10's there is approximately 1/4 to 1/2 inch of foam behind my heels. In the 9's my heel is right at the edge of the foam without coming off. THIS makes a huge difference in the comfort level, and it's where personal preference is going to come into play. I prefer a snug sandal and didn't like the heavy feeling created by the extra length in the 10's when I walked. It's not there in the 9's so I am more comfortable walking in the smaller size for longer periods of time. If you're debating between the 2 sizes I'd evaluate your own preferences. If you like a looser sandal, which won't dig in at the straps, and you don't feel like you're hanging off the end, go with the larger size. If you're more comfortable in a sandal with a tighter fit that stays with your foot better as you walk, order the smaller size.

I've attached some photos to my review with a side-by-side comparison. The 10's are on the left (black) and the 9's are on the right (brown).

Love these! I had bought my first pair of Sanuk Zen Yoga flip flops and decided I needed another pair so I wanted to try these since they have a smaller strap. I used to only wear very flat sandals and now I'm hooked on these and won't wear my others because they hurt my feet. I definitely suggest getting a size up. I usually wear a size 7-7 1/2 so I purchased a size 8 and they fit perfectly. When I first put them on, the straps felt a little snug and I have narrow feet so I'm not sure how well these would fit someone with wider feet (however, I'm almost 30 weeks pregnant and my feet seem to have swollen a little bit so that may be why)

So far so good! Like the skinnier strap style best after my Old Navy sandals needed a more sturdier replacement. I will be using them camping and hope the thicker bottom will make walking on rocks easier on my feet than Old Navy Flip flops I was wearing. Obviously much more expensive and hope I they are worth the price. Very good arch support I will say right off the bat. Pinky toes hang off a bit but not enough to bother me and I definitely have wide feet. Normally wear 7.5 (W) or 8. Purchased size 8. Would say 4/5 for initial assessment. I threw away the box and receipt so I think they are keepers! Purchased Sanuk Yoga Mat 2 same day and most definitely like these better, will be returning those not as good.

I love the concept of using yoga mats as soles for flip flops. It is what lends to this flip flop feeling EXTREMELY comfy especially for tired feet. The down side to that is that it sometimes feels a bit "tacky". It's not a big deal but should call that out especially if you have very sweaty feet.

They feel comfy just like a yoga mat. I would advise you to size up especially if you have flat/fat feet. Good everyday sandals and you can walk moderate distances in them (the pics were taken in the dentist office lol)