You will need 5 x 1” (25 mm). Rowan used #TGB4777 recycled paper buttons from Textile Garden in the UK.

Finished measurements:
Chest circumference: 41.25( 45, 48.75, 52.5, 57, 60.75, 64.5, 68.25, 73.5)“ 105( 114.5, 124, 133.5, 145, 154.5, 164, 173.5, 186.5) cm
Finished length: 21.25( 22, 22.75, 23.5, 24.5, 25.25, 25.5, 26.5, 26.75)” 54( 56, 58, 60, 62, 64, 65, 67, 68) cm
Sleeve seam:14.5( 15, 15, 15.25, 15.25, 15.25, 15.25, 15.25, 15.25)“ 37( 38, 38, 39, 39, 39, 39, 39, 39) cm

Yarn used:
Rowan Softyak DK
Shade 233 Prairie - 11( 12, 13, 14, 15, 16, 17, 18, 19) balls