This wide sash is not a practical belt for holding up trousers, it is simply for decoration, perhaps to brighten up a little black dress and emphasise the waist.

Measurements
To fit waist
64-68(72-77:82-87) cm/25-26¾(28½-30½:32¼-34¼) in
Depth
15 cm/ 6 in

additional tension
1 pattern repeat (7 sts and 26 rows) = 2.5 cm/1 in wide and 7 cm/2¾ in long over ribbon pattern on 3.25 mm needles or the size required to give the correct tension.