Yust look at sidewall of old ( if you still have them) and new LT tires for the 3 things, and give it here. Then in my answer I explain further.Sorry, but I am a but as a self-declared tire pressure idiot, I have to say that I am confused by what you are asking for.
Then if you also search for GAWR's and GVWR ( Gross Axle/Vehicle Weight Rating), empty weight, and the way you load it with als the persons, animals and luggage, I will dangerously estimate the axleloads for that, and give advice pressure with maximum reserve, at wich comfort and gripp is still acceptable.
Thanks for the help.He's asking for your info so he can manually calculate your new tire pressure, and give you the same answer as the online Calculator.
Personally, I'm going a little lower on the rears, since I don't have the box loaded.
But my answer is not totally the same as the online calculator.
I build in that max reserve, online calculator does not.
And I use an even tighter formula then the official used European formula, to my conclusions closer to ideal to laws of nature, so leads to higher pressures, even if no reserves included.
Got hold of this European formula and system end 2007, and went running with it. Got wiser in time, by reacting on fora, and asking people who knew more about it.