I normally wear a 7 1/2. I think my foot is average shaped (neither narrow or wide) with a high arch. My toe came to the very end of the size 8 I ordered. I received my size 8 1/2 fairly quickly and I love them! I am a flight attendant and need as lightweight a shoe for my suitcase as possible. But I also need adequate support without bulkiness. These are perfect! Light, comfortable, colorful, and flexible for packing. I recommend them for anyone that needs a running shoe that travels on their feet or off of their feet!