What plasterer's hawk sizes
Hawks vary in size from around 150 x 150mm (6" x 6") square to a rectangle of 500mm x 400mm (20" x 16").
Medium-sized hawks of around 300 x 300mm (12" x 12") or 330 x 330mm (13" x 13") square are the most popular, as they can hold a reasonable load but are still sufficiently light and manoeuvrable to work comfortably with.
Arm strength is the main guide as to the size of hawk you should buy. Try carrying different hawk sizes in a shop and if you find the larger sizes a strain unloaded, then you should definitely opt for a smaller size. Even if you have a big job to do, you can only carry so much mixture at a time.