This pattern was based off a sideways knit beanie from Madewell (last 3 pics) that I would not buy due to the seam up the side. I didn’t gauge it properly, but I think 5 stitches in 2 x 2 ribbing is about an inch. When the hat lay flat, it was about 9 inches across.

The first picture is of the hat pre-blocking. As you can see, it was a bit stiff and not slouchy at all until I blocked it.The last three are after blocking.