Fit is more about what looks and feels right, rather than actual measurements. Some people prefer a bigger hat, for comfort; others like something which feels good and tight. Still others will accept a pinch to the skull to get just the right image in the mirror.
The shape of your face can determine which styles look best. Ultimately, however, only you can decide which hat or style is the best reflection of your true character. Consider these guidelines:
Long/Slender Face: The best hat for a long, slender face would be anything with a low profile. A Driver or Pork Pie Fedora – even a Gambler style or Visor would do well. A wide brim can also add charm to your character.
Short Face: A short face allows the character to use a lot of vertical space. Wear a high-profile crown, or a tapered crown help to create the illusion of a more elongated facade. A narrow brim is best, to avoid overshadowing your features.
Square Face: A square face usually comes with a nice jaw! Look for crowns that are more round than square, and choose a profile that is no higher than one-half the height of your head (from chin to crown). You can wear a wide or narrow brim – it all depends on the ratio of the crown.
Round Face: Soft lines are beautiful. Accentuate those lines with a hat that takes on a few more angles, such as a crown with a square look to it. You can wear a wider brim – not too wide, unless you’re avoiding the sun — but around 2 ½ inches out from the break should look very nice. Try to stick to bands that are less than 1” in width.
Small Face: “Cute as a button” – you may have heard this your whole life. The bonus? You can wear big, floppy brims, but also narrow brims, close-fitting beanies, buckets and cloches. Not many people can wear these styles, so take advantage!