22½" [57 cm] at brim and 10" [25.5 cm] from brim to crown
sparrow / port 207 / 2 skeins
16" circular in size US 4 [3.5 mm] / set dpns in size US 4 [3.5 mm]
24 sts and 36 rows = 4" [10 cm] in stockinette stitch, after blocking
Hat is knitted in the round from brim to crown.
Long-tail cast on (link), decreasing.