This is a common concern among many first time FiveFinger buyers. Whether you ordered online or bought at the store, some of you may be second guessing your decision on size after wearing your FiveFingers for a day or two. Here is how you know if your FiveFingers are too tight and need to be returned for a different size.
Vibram FiveFingers should fit like a glove. Your heel should sit securely in the heel cup and your toes should be near the end of the toe pockets. Most people that have sizing concerns worry if their big toe is too long for their FiveFingers. With traditional shoes you never want your big toe to touch the front portion of the shoe, because this will cause lots of discomfort. FiveFingers are different and do not fit like your old shoes. It may be ok if your big toe is touching the front edge as long as your foot doesn't feel squeezed into the FiveFingers. What some people think is too tight is could be a near perfect fit. However, if there is absolutely no room in the big toe pocket and your foot or toe is hurting or there is a lack of circulation, the fit is too tight.
Our advice is to go back to the store if you are feeling too much discomfort to wear your FiveFingers around the house for extended periods of time. The FiveFingers are supposed to be an extension of your foot. A loose fit is probably worse than what feels like a slightly tight fit. Also, most people that claim to have a tight fit say that after wearing them for a week or so, their FiveFingers loosened up. The message here is to not panic if you aren't hurting from just casual wear. Let your FiveFingers break-in by wearing them around the house, taking a couple walks, and doing some light running. Some slight discomfort is common among first timers and what feels tight may be the glove-like fit that you need.
Here's what Vibram says:
HOW SHOULD MY FIVEFINGERS FIT?
"Ideally, you will want your toes and heel to fit into each pocket comfortably snug, with your longest toe grazing the end of the toe pocket. You do not want the standard 1/2 inch of “wiggle” room as desired in traditional footwear."
"Although it is perfectly fine for your toes to graze the end of the toe pockets, make sure that each toe can extend fully. If any of your toes are scrunched or curled due to lack of space, you need to go up in size. Alternately, if you wiggle your toes and they slip out of the toe pockets, you need to go down in size. Ultimately, you should find a pair that you are comfortable in and that allow you to perform activities freely and naturally—as if you are wearing no shoes at all!"