Most people have at least a quarter size difference between their left and right feet. To find your perfect fit, we’ll send you three pairs of Atoms for you to compare sizes. Try all three pairs, and keep the individual shoes that fit best — for example, a size 7.75 on your right foot and an 8 on your left. Send back the other two pairs within 7 days using the included pre-labeled shipping box and tape. 

We suggest starting with the size you normally wear, and we will reccomend quarter sizes based on whether or not you sometimes size up or size down.

All sizes are US based.