getting the titleBar height

[MrPolite]

can someone just double-check my code? cuz it seems to be working almost fine except its one pixel off for some reason

Public ReadOnly Property TitleBarHeight(ByVal bStyle As FormBorderStyle) As Integer
        Get
           Select Case bStyle
                Case FormBorderStyle.Fixed3D
                    Return SystemInformation.CaptionHeight + _
                                  2 * SystemInformation.Border3DSize.Height
 
 
                Case FormBorderStyle.Sizable, FormBorderStyle.FixedSingle, FormBorderStyle.FixedDialog
                    Return SystemInformation.CaptionHeight + _
                             2 * SystemInformation.Border3DSize.Height
 
 
 
                Case FormBorderStyle.FixedToolWindow, FormBorderStyle.SizableToolWindow
                    Return SystemInformation.ToolWindowCaptionHeight + _
                             2 * SystemInformation.Border3DSize.Height
 
                Case FormBorderStyle.None
                    Return 0
            End Select
        End Get
    End Property

The first case switch returns a value 1 pixel less than the actual value, and the second case statement returns 1 pixel more than the actual value. I think I'm using the right stuff, why isn't it working correctly?