WebListBox in a WebControl

If the web listbox grows to the point that scroll bars would be required, is there a way to figure out from the number of rows what the size height would be without requiring a scroll bar?

Listbox.ListCount*ListBox.RowHeight

listbox.top + listbox.listcount * listbox.rowheight ,

BUT

depending on your styles etc, and the way its rendered by the browser you will still get occasions where the scrollbar will show.

i add an amount based on the rowcount so its 120% or similar, still it doesn’t always work.