Automatic Width and Height
<UserControl x:Class='SilverlightApplication3.MainPage' xmlns='http://schemas.microsoft.com/winfx/2006/xaml/presentation' xmlns:x='http://schemas.microsoft.com/winfx/2006/xaml' xmlns:d='http://schemas.microsoft.com/expression/blend/2008' xmlns:mc='http://schemas.openxmlformats.org/markup-compatibility/2006' mc:Ignorable='d' d:DesignWidth='640' d:DesignHeight='480'> <Grid Background="Beige" ShowGridLines="True"> <Grid.ColumnDefinitions> <ColumnDefinition Width="Auto" /> <ColumnDefinition /> </Grid.ColumnDefinitions> <Grid.RowDefinitions> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> <RowDefinition Height="Auto" /> </Grid.RowDefinitions> <TextBlock Grid.Column="0" Grid.Row="0">This is a test.:</TextBlock> <TextBlock Grid.Column="1" Grid.Row="0">This is a test</TextBlock> <TextBlock Grid.Column="0" Grid.Row="1">This is a test:</TextBlock> <TextBlock Grid.Column="1" Grid.Row="1">This is a test</TextBlock> <TextBlock Grid.Column="0" Grid.Row="2">This is a test:</TextBlock> <TextBlock Grid.Column="1" Grid.Row="2">This is a test</TextBlock> </Grid> </UserControl>