Simply wrapping your XAML content in a
Viewbox
will automatically zoom the contents out so they all fit in the viewable area:
<Viewbox>
</Viewbox>
Simple as that. If you want to Zoom out dynamically or to a specific amount then you can use a
ScaleTransform
:
<Grid>
<Grid.RenderTransform>
<ScaleTransform ScaleX="0.5" ScaleY="0.5" CenterX="0.5" CenterY="0.5" />
</Grid.RenderTransform>
</Grid>