Child's small: 41cm/16in unstretched, to fit 46cm/18in
Child's large: 46cm/18in unstretched, to fit 51cm/20in
Adult: 51cm/20in unstretched, to fit 56cm/22in
To make the sides of this hat longer or shorter, simply work more or fewer repeats of Cable round 2. The post-stitch ribbing makes the hat very stretchy so the three sizes given should fit from toddler to adult.
Turn the hat inside out to transform the vertical ribbed pattern into a horizontal one!
Please note that the pattern for sale through ravelry has express permission to sell your finished items for charity & for personal profit as long as I am given credit for the design.