Topic: KA-n/RA-n Hull sizes

I've been trying to workout how the hull size is calculated in the new Klingon and Romulan Armada books. Why? because I want to use those ships which will not get into the Armada books any time soon (if ever) like the earlier stuff and the variants. Most of the values seen to be a straight numeric conversion and I found the spreadsheet for calculation thrust.

I know the hull is not calculated as per nova build rules and have been using the ship descriptions on the ADB site for Federation Commander Squadron level. Just counting the Hull boxes gives a very close approximation but some times its high and some times low. Adding any box not used for anything else ie Aux boxes and then making an adjustment seems to make the results more varied.

Any clues would be appreciated.