Depends on the offset man. Take your stock (known) wheels, measure it all up. Find the offset on the stockies, find the width, measure out how far it has to go, to run as flush as you want, then you know how much wider you need to go if you keep the same offset. If you go for higher offset, you can go for wider tyres. But that's the lame way of doing it. Wheel poke = hot.
...if you CBF measuring it up, go to a tyre shop and test fit a bunch.