True size of my MDI Client area - height - 14?

Question

I am trying to center an MDI Child window in the center of my parent window's client area. By trial and error, I had found the following to work:

((parent.ClientSize.Width - 4)-centerchild.Width)/2, ((parent.ClientSize.Height - 14)-centerchild.Height)/2

I figured the 4 that I subtract from the width is the size of the border on either side, and I am able to get that number by either getting the MDIClient control within the parent (thanks to stack overflow for my finding that), or by subtracting SystemInformation.Border3DSize.Width * 2. This makes sense to me.

I am having a much harder time figuring out why I need to subtract 14 from the height. Assuming the bottom border is 2, that still leaves a number of 12 which I cannot reconcile with anything. (If there's also a top border of 2, then t hat still leaves 10 unexplained.) I have looked into the following:

• Getting the MDIClient control within the parent does not get me that exact height as it does the width. Rather, it gets me parent.ClientSize.Height - 28, which is double the difference I worked out by trial and error. 28 might represent a bottom border (2) + a top border (2) + the height of the menu strip (24), but that does not explain the 14 that I have found to be perfect.
• The Menu Strip height - as I said above, that's 24.
• Various other window-element measures in SystemInformation. Perhaps I overlooked one, but nothing seems to explain it to me.

I could certainly use the code with my trial and error numbers, but I hate to not understand. Does anyone have any ideas that would explain the (total) height difference of 14?