I just stuck and large sheet cake in my oven but I don't really know how long it should bake? any ideas?

12x18, start checking at about 50 minutes!

depends on how full the pan is filled. My 12x18 cook at 325 in about 35-40 minutes. But they are only 1 inch tall.

Good point Euphoria, I'm a 2-inch pan filled 2/3rds kind of girl myself!

I would say 50 to 55 mins.

Then yeah I would say about 50-55 minutes. I myself like a tall cake as well, but I don't like to torte. So I usally make two one inch cakes and stack them.

It will also depend on your oven. To be safe I would check it after about 45 minutes.

I'm with traci. I'm new at this too, but I'd check after 45 mins and go from there.

Thanks you all, It took about 45-50 minutes or so...just like you said