Slade618

I have a 2014 Lariat 4x4 with a Leveling kit currently riding on 35" Lexani Mud Beasts with the Factory 20x9 Ford wheels. I want to put on the Bushwacker Pocket flares model # 20929-02 flares which will stick out 1.5" front and rear with a 6" tall flare. This model is 1 of 2 that are listed for my truck model. the other flares stick out 2.38" in front and 2" in the rear. So, again I'm just guessing at the lesser of the two assuming that the bigger set of flares is for an even bigger tire than 35". So assuming I go with the 1.5" flare front and rear and I have found a wheel made by Fuel that I really like called the "Dune". I'm looking at the 20 x 12 sized wheel, now I need to figure out what kind of offset I will need. Is there a way to figure out what wheel Offset I will need, to have the tire stick out about 1" past the Flare or do I need to wait until the flares are added and then take some sort of measurement?