Okay, I'm looking to purchase a house which will cost about $280k. I just need to know how much my monthly payments would be at 4.5% interest for 30 years. I know there's some kind of formula, but I don't know what it is.

I don't want to go to a loan officer quite yet because I don't feel like filling out all the paperwork and getting my credit pulled and stuff. I feel like if I went, I would be rushed into something.

Anyway, if there's any math wizzes out there, let me know.
thanks