Bind to Grid Width and Height
<Grid xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Name="grid"> <StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center"> <TextBlock Text="{Binding ElementName=grid, Path=ActualWidth}" /> <TextBlock Text=" × " /> <TextBlock Text="{Binding ElementName=grid, Path=ActualHeight}" /> <TextBlock Text=" device independent units" /> </StackPanel> </Grid>