The formula* I've came up with was for my 10x SSJ multiplier list** that I finished today (did some 10x lists before, but today I changed my Goten and Kid Trunks' placement).
*Formula =
2A x 180
2.3 ^ D
**Goten and Kid Trunks' power levels on my 10x SSJ list
Goten [pre RoSaT] 330,000,000
~SSJ 3,300,000,000
Kid Trunks [pre RoSaT] 340,000,000
~SSJ 3,400,000,000
Applying in the formula we'd have:
base Gotenks ~ 50,000,000,000 [would like to have him a bit lower, but if he ends up a good amount < Fat Boo, then it's all fine]
SSJ Gotenks ~ 100,000,000,000 [I have Goku SSJ3 at 90 billions, then 100 billions works just fine]
Post RoSaT, I have to bump up Goten and Trunks to 500,000,000 [a rather big increase, but still nothing compared to Gotenks' increase] and I manage to have base Gotenks around 180 billions, which is a whooping 1.8x gap compared to his pre RoSaT SSJ self.