This is a simple and easy pattern for a slouch beanie made for medium sized adult. A special request from my son. He didn't want the hat to be too wide at the crown area.

Materials: 

Medium Weight Yarn (I used Red Heart Super Saver)

5mm Crochet Hook 

Gauge:
15 ch = 3 inches
3 rows of dc = 1.5 inch

Abbreviations used:
st = stitch
ch = chain
sl st = slip stitch
sc = single crochet
dc = double crochet

Procedure:

Round 1: Start with a magic ring.Ch2 (doesn't count as dc), dc 24. Sl st to join.

Round 2: Ch 2, dc in same st, 2dc in next st. *Dc in next st, 2 dc in next.** Repeat from * - ** until end. Sl st to join.

Round 3: Ch 2, dc in same st, dc in next st and into the Remaining Sts. Join.

Round 4: Ch 2, dc in same st, dc in next st, 2dc in next st. *Dc in next 2 sts, 2 dc in next.*** Repeat from * - ** until end. Sl st to join.

Round 5:  Ch 2, dc in same st, dc in next st and into the remaining sts. Join.

Round 6:  Ch 2, dc in same st, dc in next 2 sts, 2dc in next st. *Dc in next 3 sts, 2 dc in next.*** Repeat from * - ** until end. Sl st to join.

Round 7:  Ch 2, dc in same st, dc in next st and into the remaining sts. Join. (For medium size, proceed to Round 10)

For Large size only: Round 8 and 9

Round 8: Ch 2, dc in same st, dc in next 3 sts, 2dc in next st. *Dc in next 4 sts, 2 dc in next.*** Repeat from * - ** until end. Sl st to join.

Round 9:  Ch 2, dc in same st, dc in next st and into the remaining sts. Join.

Round 10: Ch 2, dc in same st, dc in next st and into the remaining sts. Join.
Round 11- 20: Repeat Round 10.

Round 21: Ch 1, sc in same st, sc in next st and into remaining sts. Join.

Round 22 - 24 (or until desired length): Repeat Round 21. Join.
Fasten off and weave ends.