What is the correct cereal/milk ratio?

Just enough so that, by the time I finish the cereal, there's only a little milk left.

Edit: The way I do it is to have a layer of granola on the bottom, then a layer of whatever floaty cereal on top. When I fill it with milk, it's a little bit below the top layer so that it's just a little less than what would make it float. That usually gives me the perfect ratio.