You will need six buttons. Rowan used # BV1800 from Bedecked.

Finished measurements:
Body circumference:
35.5(40, 43.5, 47.5, 51)“
90(101, 110, 121, 1310 cm

Finished length:
17(17.5, 18.5, 19.5, 20)“
43(45, 47, 49, 51) cm

Sleeve length to underarm:
17.5(17.5, 18, 18, 18)“
45(45, 46, 46, 46) cm

Yarn used:
Rowan Alpaca Classic
109 Deep Teal - 6( 6, 7, 8, 8) balls