As an extra detail

32 or 40 inches] and 9 mm [US13] / 40 and 60 cm [16 and 24 inches]

The button holes are constructed at the end by widening up a hole in the knit fabric (and are thus not worked as you knit the button band)

6 mm zipper

which in the given example would give you 30 cm [11¾ inches] of positive ease

Everyday Socks LANGUAGE:Norsk As an extra detailThe Everyday Socks are worked from the cuff to the toe. The socks are worked in stockinette stitch either in stripes or in one solid color. The heel is shaped with short rows. Sizes: EU shoe sizes: 35 36 (37 38) 39 40 (41 42) 43 44 US womens shoe sizes: 5 6 (6 7) 8 9 (9 10) 11 12 Gauge: 30 sts x 40 rows = 10 x 10 cm [4 x 4 inches] in stockinette stitch on 2. 5 mm [US1] needles Needles: Double pointed needles: 2. 5 mm [US1] (or a 2. 5 mm [US1] 60 or 80