Form a slip knot to put the stitches of the first round in.
1. Round: 2 chain stitches, 7 sc = 8 stitches (st)
2. Round: *sc, sc 2 in 1 st* repeat * to * 3 times = 12 st, place a stitch marker (pm) in the last st
Move on crocheting without slip stitches to the end of round 2 and chain stitches in the beginning of round 3.
3. Round: *sc 2 in 1 st, sc* repeat * to * 5 times = 18 st, pm in the last st
4. Round: *sc, sc 2 in 1 st, sc* repeat * to * 5 times = 24 st, pm in the last st
5. Round: *sc 2 in 1 st, 3 sc* repeat * to * 5 times = 30 st, pm in the last st
6. Round and every following round: sc and increase 6 st in the explained manner. Take care that the increases are at alternating parts of the rounds.
When you have almost the needed amount/width, increase as many stitches as you need to get the calculated amount for the circumference of your head.
Now go on simple crocheting. When the hat has the desired length, do 1 round of crab stitch. Sew in the yarn.
Knit an i-cord of about 5-6 cm length. Thread the icord through the hat as it is shown in the pictures and sew the ends together at the inside of the hat. The holes where the i-cord goes through are 2 cm above the brim and next to each other.