From the pattern notes: “Instructions are written in four sizes: small (child’s 4 to 5, head size about 18 1/2”); medium (child’s 6 to 8, head size about 19 1/2”); large, (child’s 10 to 12, and also for a small adult hand - up to abot a 6 1/2” adult glove size; head size about 20”); and adult (for the average adult hand size, about a 7 to 8 1/2 glove size, head size about 21”).”