This Myssy is One Size / M and it fits 85% of our customers. It fits well for hat sizes between 54 to 59 cm. Each Myssy is unique, and though all our grannies work off from the same size chart, not all hats are precisely the same.
All Myssy hats should feel a little tight in the beginning, the hat adjusts to the size and shape of your head within the first week of use.