Math to get relative scale from level stack

Question

Apologies for the horrible title. I spent 10 minutes trying to explain this in one sentence and failed.

Although the application prompting this question is in Java (And

Answer 1

so far...

public static void getZoom(int currentLevel, double userScale){
        double ns = (1 << (currentLevel - 1)) * userScale;
        int newLevel = 1;
        int ts = 1;
        while(ts < ns){
            ts <<= 1;
            newLevel++;
        }
        double newScale = ns / ts;
        System.out.println(newLevel + ", " + newScale);
    }