Thickness of 1cm, 1.2cm, 1.5cm, 2cm, 3cm and up are available regarding to your projects requirements. Common slabs thicknesses are 2cm and 3cm.
Common metric sizes:
30×60, 40×40, 40×60, 40×80, 60×60, 60×90, 80×80, 90×90
Common imperial sizes:
12×12, 12×18, 12×24, 16×16, 16×24, 18×18, 24×24, 24×36, 32×32, 36×36