I wrote this pattern for first time knitters or anyone in need of a quick, warm hat.

Finished Size:
Sizing for newborn through adult large

Circumference:
11.2 (12.8, 14.4, 16.0, 17.6, 19.2, 20.8, 22.4) in
28.4 (32.5, 36.6, 40.6, 44.7, 48.8, 52.8, 56.9) cm

Length:
5.5 (6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0) in
14.0 (15.2, 16.5, 17.8, 19.1, 20.3, 21.6, 22.9) cm

Yarn:
1 skein of Malabrigo Rasta (super bulky, 90 yards/150 grams) or any super bulky yarn.

The variegated blue sample is an adult large (22.4 in / 56.9 cm), shown in the color Solis and used almost the entire skein (140 g / 84 yd). The light green sample is an adult small (19.2 in / 48.8 cm) shown in the color Cucumber and used 110 g / 66 yd.

Rasta is available at my LYS but there are many options such as Cascade Magnum, Lion Brand Thick and Quick, and Wool and the Gang Crazy Sexy Wool.

Gauge:
10 stitches x 14 rows = 4in / 10cm in 1x1 rib (k1, p1)

Needles and Notions:
Size 9mm (US13) circular knitting needles with a 16in cord, or size needed to obtain gauge
Stitch marker
Darning needle
Pom pom (optional)

Notes:
Hat is worked in the round from the bottom up

Sizing recommendations
The ribbing is quite stretchy giving flexibility with sizing.

If you prefer your hats looser, I recommend selecting a size about 2 in (5 cm) smaller than your head circumference.

If you prefer your hats tighter, you could select a size about 4 in (10 cm) smaller than your head circumference.

The adult large, darker blue, (22.4 in / 56.9 cm) sample is shown on a 23 in (58 cm) head giving a very loose and slouchy fit.

The adult small, light green, (19.2 in / 48.8 cm) sample is shown on a 23 in (58 cm) head giving a snugger fit but still very comfortable.