How should I set the LargeChange property of a scrollbar so the thumb is a proportional size for the Max value?

Basically, I want my scrollbar to beh开发者_StackOverflow社区ave like a scroll panel scrollbar. What algorithm, given the min and max values, should I give to the large change so that the thumb sizes up with how the scroll bar in a panel would to its contents?

EDIT: What I'm looking for is like a, "it multiplies the maximum value by x.xx until xx" or something

A scrollbar handles the thumb size automatically. Just figure out your scroll range and page size.

If you want other information, I recommend editing your question to make it less general.