I gave a high estimate for the yarn since I wouldn’t want anyone to run out before closing up the hat. The amount I used was 1.58 oz of yarn, using a converter online (I used 45grams) so I tried to get the yardage for you. This was what I used for my 6 y/o son’s hat, you might need more for an adult hat or a bigger head of any age. Though this hat for my son did fit on the mannequin head I have to model my hats.