Read this tip to make your life smarter, better, faster and wiser. LifeTips is the place to go when you need to know about Starting a Project and other Crochet topics.
When working in the round to make a hat, mathematics realy helps to figure out the right size. First, measure around the hat recipient's head, just right above the ears and across the forehead. That will give you the circumference or perimeter of the finished hat. Divide that number by pi (3.14159). That will give you the diameter (straight line measurement across the widest part) of the circle that you will crochet before you start to decrease to make the sides and brim of the hat.