I’m going for a hat circumference of 19 inches for this 10-year-old, allowing for a 2-inch negative ease, so casting on 38 stitches. This chart was helpful in terms of sizing: KnitPicks Hat Size Chart. It’s also helpful to know that the number of stitches you cast on is increased by 50% once you begin the brioche pattern.

I was able to knit the body of the hat to 9 inches. I shortened the crown area by four rows, skipping a few of the p1, k1 rows in the crown (3-5 and 8), but did all the decrease rows, ending with six stitches. I used Nimble Needles alternate method of doing the p3 decreases.

I had 2 grams of yarn left after weaving in ends.