Yes, the sizes of Asha are cut to the same size dimensions as natural diamonds, and the Asha's are already listed in diamond weight equivalents on the website.
Thus, the dimensions of a 2ct well-cut diamond and 2ct Asha are identical, so you can just order the carat weight you want, and it is already calibrated to match that of natural diamonds.
Example: a round H&A 1ct diamond is 6.5mm diameter, the Asha 1ct H&A round is also 6.5mm diameter.