Set VerticalAlignment/HorizontalAlignment for Button
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Window1" Height="300" Width="300"> <WrapPanel ItemWidth="40" ItemHeight="40"> <Button Width="30">A</Button> <Button Padding="10 10">B</Button> <Button Padding="30 30">C</Button> <Button Margin="10 10">D</Button> <Button HorizontalAlignment="Right">E</Button> <Button HorizontalAlignment="Left" >F</Button> <Button HorizontalAlignment="Stretch">G</Button> <Button Width="30" VerticalAlignment="Top" HorizontalAlignment="Left">H</Button> <Button Width="30" VerticalAlignment="Bottom" HorizontalAlignment="Right">I</Button> <Button Width="60" Height="60">J</Button> <Button Width="30">K</Button> <Button Width="30">L</Button> <Button Width="30">M</Button> <Button Width="30">N</Button> <Button Width="30">O</Button> <Button Width="30">P</Button> </WrapPanel> </Window>