You will need a circular needle at least 48” (120 cm) for the front cross bands.

Finished measurements:
Back measurement: 20(21.5, 24, 25.5,28)“ 50.5(55, 60.5, 65, 70.5) cm
Finished length: 18(19, 19.5, 20.5, 21.5)” 46(48, 50, 52, 54) cm
Sleeve length to underarm: 17.5(17.5, 18, 18, 18)“ 45(45, 46, 46, 46) cm

Yarn used:
Rowan Kidsilk Haze
romand 681 - 5(5, 5, 6, 6) balls