You will need 7 buttons, approximately 1” (25 mm). Rowan used metal buttons from Textile Garden in the UK.

Finished measurements:
Chest circumference: 42( 45.75, 49.75, 53.25, 57.75, 61.5, 65.5, 69.5, 73.5)“ 106.5( 116.5, 126.5, 136.5, 146.5, 156.5, 166.5, 176.5, 186.5) cm
Finished length: 28.775( 29.5, 30.25, 31, 32, 32.75, 33, 33.5, 34.25)” 73( 75, 77, 79, 81, 83, 84, 86, 87) 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 Tweed Haze
Shade 552 Rainy - 7(8, 9, 9, 10, 11, 12, 13, 13) balls