Yarn Type

Hi,
I found a pattern from Caron for an elegant hat. The material states Simply Soft Heather yarn and size G crochet hook. I used Simply Soft in a sage color. It is also a 4 medium yarn.
I am using a J hook and it is still smaller than I would like. I know gauges can be different, but from a G to a J seems off the charts. I don't crochet tightly as a rule, so I don't understand what the problem is with this. Both are 100% acrylic yarn. Does anyone know if there is any difference in the yarn between simply soft and simply soft heather that I am not aware of?
Also, the gauge states - in single crochet, 15 sts and 14 rows = 4"/10 cm. I am having difficulty measuring stitches in the round. Anyone have any suggestions that would help?
I'd really like to make this project. I'd appreciate any help.
Thank You

Janie,

Usually with number four yarn, it is recommended by the manufacturers to use size I to K hook. I know that patterns will vary by the hook stated.

Here is a resource which hopefully is helpful on measuring guage in the round:

How to Measure Gauge in the Round - For Dummies

Janie,

By the way - welcome to the group! It is nice to have you on board! Others will be checking in a different times of the day and night, as well! They may be able to give you some different insights!