It depends on how deep the pan is.
It depends on the depth of the pan
for an 14 in round cake pan, you only need 1 box
4 boxes for a single pan
It depends on how deep the cake pan is.
The boxes I checked said one box would make a 13x9, so you will need about 1 1/2 boxes for a 12x18. Assuming the pan is deep enough you could use two boxes for a one layer 12x18 or you may want to make a two layer cake using 1 1/2 box per layer.
There are 11 cups of batter in an 11x15 pan for a 2 inch layer. I would guess for an 11x13, maybe 10 cups?
yes, it wont be that tall but it will work ok.
A 9" X 13" baking pan would work well.
With a regular cake pan, there really would be no way to get the cheese cake out easily. However, if you want the perfect roundness with straight sides of a cake pan with easy removal, I would recommend a tart pan, which is a round pan that has a removable bottom. If you liberally butter the cake pan then when the cheese cake is done, refrigerate it until it's cold. Set the cake pan in warm water for about 15 seconds. Turn the cake out onto a plate by putting the plate over the cake pan and turning the whole thing upside down. Repeat this to turn it back onto a serving dish.
It will probably take 1-1/2 boxes. Fill the pan roughly half full & use the rest for cupcakes.
The farberware 9-inch cake round cake pan is the cheapest one. You can purchase this pan online for $6.95.
In a 12" x 17" pan? Don't do it, that will overflow. You can barely bake two boxes per sheet, it's nearly too much. As for the timing for two boxes, it's about 35-45 minutes at 325-350 degrees.