The sizes of the Thoth deck (currently available) are as follows:
Pocket / Mini: 3 1/2 x 2 1/4 inches, or 89 x 58 mm. 1 inch or 25 mm thick.
Small: 4 5/16 x 2 3/4 inches, or 110 x 70 mm. 1 inch or 25 mm thick.
Standard: 5 1/2 x 3 3/4 inches, or 140 x 95 mm. 1 inch or 25 mm thick.
They all seem to be about the same in thickness, i.e., similar card stock.