From Infiknit website:

V-necked cardigan knitted with vertical bands of cables and textured stitches, with ribbed welts, cuffs, and button bands. Worked in worsted weight yarn and sized for a finished chest measurement of 40, 44, 48, 52, 56 inches. Yarn requirements for 4oz skeins od worsted weight yarn approx 220yds per 4oz. Tension 22 sts over 4”(10cm) on 4.5mm(US7) needles.

40 - 6 skeins
44 - 7 skeins
48 & 52 - 8 skeins
56 - 9 skeins