diff --git a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
index 2ee8df78ef..fd2e4c3355 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/ViewModels/ControlLayoutViewModel.cs
@@ -11,7 +11,10 @@ namespace Avalonia.Diagnostics.ViewModels
         private Thickness _marginThickness;
         private Thickness _borderThickness;
         private Thickness _paddingThickness;
-        private string _sizeText;
+        private double _width;
+        private double _height;
+        private string _widthConstraint;
+        private string _heightConstraint;
         private bool _updatingFromControl;
 
         public Thickness MarginThickness
@@ -32,10 +35,28 @@ namespace Avalonia.Diagnostics.ViewModels
             set => RaiseAndSetIfChanged(ref _paddingThickness, value);
         }
 
-        public string SizeText
+        public double Width
         {
-            get => _sizeText;
-            private set => RaiseAndSetIfChanged(ref _sizeText, value);
+            get => _width;
+            private set => RaiseAndSetIfChanged(ref _width, value);
+        }
+
+        public double Height
+        {
+            get => _height;
+            private set => RaiseAndSetIfChanged(ref _height, value);
+        }
+
+        public string WidthConstraint
+        {
+            get => _widthConstraint;
+            private set => RaiseAndSetIfChanged(ref _widthConstraint, value);
+        }
+
+        public string HeightConstraint
+        {
+            get => _heightConstraint;
+            private set => RaiseAndSetIfChanged(ref _heightConstraint, value);
         }
 
         public bool HasPadding { get; }
@@ -65,6 +86,29 @@ namespace Avalonia.Diagnostics.ViewModels
             }
 
             UpdateSize();
+            UpdateSizeConstraints();
+        }
+
+        private void UpdateSizeConstraints()
+        {
+            if (_control is IAvaloniaObject ao)
+            {
+                string CreateConstraintInfo(StyledProperty<double> minProperty, StyledProperty<double> maxProperty)
+                {
+                    if (ao.IsSet(minProperty) || ao.IsSet(maxProperty))
+                    {
+                        var minValue = ao.GetValue(minProperty);
+                        var maxValue = ao.GetValue(maxProperty);
+
+                        return $"{minValue} < size < {maxValue}";
+                    }
+
+                    return null;
+                }
+
+                WidthConstraint = CreateConstraintInfo(Layoutable.MinWidthProperty, Layoutable.MaxWidthProperty);
+                HeightConstraint = CreateConstraintInfo(Layoutable.MinHeightProperty, Layoutable.MaxHeightProperty);
+            }
         }
 
         protected override void OnPropertyChanged(PropertyChangedEventArgs e)
@@ -99,11 +143,9 @@ namespace Avalonia.Diagnostics.ViewModels
             {
                 _updatingFromControl = true;
 
-                var updateSize = false;
-
                 if (e.Property == Visual.BoundsProperty)
                 {
-                    updateSize = true;
+                    UpdateSize();
                 }
                 else
                 {
@@ -120,16 +162,16 @@ namespace Avalonia.Diagnostics.ViewModels
                         else if (e.Property == Border.BorderThicknessProperty)
                         {
                             BorderThickness = ao.GetValue(Border.BorderThicknessProperty);
-
-                            updateSize = true;
+                        } 
+                        else if (e.Property == Layoutable.MinWidthProperty ||
+                                 e.Property == Layoutable.MaxWidthProperty ||
+                                 e.Property == Layoutable.MinHeightProperty ||
+                                 e.Property == Layoutable.MaxHeightProperty)
+                        {
+                            UpdateSizeConstraints();
                         }
                     }
                 }
-
-                if (updateSize)
-                {
-                    UpdateSize();
-                }
             }
             finally
             {
@@ -141,9 +183,8 @@ namespace Avalonia.Diagnostics.ViewModels
         {
             var size = _control.Bounds;
 
-            size.Deflate(BorderThickness);
-            
-            SizeText = $"{size.Width} × {size.Height}";
+            Width = size.Width;
+            Height = size.Height;
         }
     }
 }
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
index 1487cb6dde..42e64d59ae 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml
@@ -106,15 +106,48 @@
 
     <Grid Grid.Column="2" RowDefinitions="Auto,*" >
       <TextBlock Grid.Row="0" Text="Layout Visualizer" Margin="4" />
-      <local:ThicknessEditor Grid.Row="1" Margin="8,0,8,8" Header="margin" VerticalAlignment="Top" HorizontalAlignment="Center" Background="{StaticResource MarginBackgroundBrush}" Thickness="{Binding Layout.MarginThickness}">
-        <local:ThicknessEditor Header="border" Background="{StaticResource BorderBackgroundBrush}" Thickness="{Binding Layout.BorderThickness}" IsPresent="{Binding Layout.HasBorder}">
-          <local:ThicknessEditor Header="padding" Background="{StaticResource PaddingBackgroundBrush}" Thickness="{Binding Layout.PaddingThickness}" IsPresent="{Binding Layout.HasPadding}">
-            <Border BorderThickness="1" BorderBrush="{StaticResource ThicknessBorderBrush}" MinWidth="100" MinHeight="16" Background="{StaticResource SizeBackgroundBrush}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
-              <TextBlock Margin="2" HorizontalAlignment="Center" VerticalAlignment="Center"  Text="{Binding Layout.SizeText}" />
-            </Border>
+      
+      <Grid Grid.Row="1" x:Name="LayoutRoot" Margin="8,0,8,8" RowDefinitions="Auto,Auto" ColumnDefinitions="Auto,Auto">
+
+        <Border x:Name="VerticalSize" Grid.Row="0" Grid.Column="1" >
+          <TextBlock VerticalAlignment="Center" FontWeight="Bold"
+                     TextDecorations="{Binding Layout.HeightConstraint, Converter={x:Static local:Converters.HasConstraintConverter}}"
+                     Text="{Binding Layout.Height}"
+                     ToolTip.Tip="{Binding Layout.HeightConstraint}" />
+        </Border>
+        
+        <Border x:Name="HorizontalSize" Grid.Row="1" Grid.Column="0" >
+          <TextBlock HorizontalAlignment="Center" FontWeight="Bold" 
+                     TextDecorations="{Binding Layout.WidthConstraint, Converter={x:Static local:Converters.HasConstraintConverter}}"
+                     Text="{Binding Layout.Width}" 
+                     ToolTip.Tip="{Binding Layout.WidthConstraint}" />
+        </Border>
+        
+        <local:ThicknessEditor Grid.Row="0" Grid.Column="0" Header="margin" VerticalAlignment="Top" HorizontalAlignment="Center" Background="{StaticResource MarginBackgroundBrush}" Thickness="{Binding Layout.MarginThickness}">
+          <local:ThicknessEditor x:Name="BorderArea" Header="border" Background="{StaticResource BorderBackgroundBrush}" Thickness="{Binding Layout.BorderThickness}" IsPresent="{Binding Layout.HasBorder}">
+            <local:ThicknessEditor x:Name="PaddingArea" Header="padding" Background="{StaticResource PaddingBackgroundBrush}" Thickness="{Binding Layout.PaddingThickness}" IsPresent="{Binding Layout.HasPadding}">
+              <Border x:Name="ContentArea" BorderThickness="1" BorderBrush="{StaticResource ThicknessBorderBrush}" MinWidth="100" MinHeight="16" Background="{StaticResource SizeBackgroundBrush}" VerticalAlignment="Stretch" HorizontalAlignment="Stretch">
+                <TextBlock Margin="2" HorizontalAlignment="Center" VerticalAlignment="Center" Text="content" />
+              </Border>
+            </local:ThicknessEditor>
           </local:ThicknessEditor>
         </local:ThicknessEditor>
-      </local:ThicknessEditor>
+
+        <Canvas Grid.Row="0" Grid.Column="0" Grid.RowSpan="2" Grid.ColumnSpan="2">
+          <Canvas.Styles>
+            <Style Selector="Rectangle">
+              <Setter Property="StrokeDashArray" Value="1,3" />
+              <Setter Property="Stroke" Value="#333333" />
+              <Setter Property="StrokeThickness" Value="1" />
+            </Style>
+          </Canvas.Styles>
+          <Rectangle x:Name="HorizontalSizeBegin" />
+          <Rectangle x:Name="HorizontalSizeEnd" />
+          <Rectangle x:Name="VerticalSizeBegin" />
+          <Rectangle x:Name="VerticalSizeEnd" />
+        </Canvas>
+      </Grid>
+      
     </Grid>
   </Grid>
 
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
index c6bd5a18aa..c9568509f6 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ControlDetailsView.xaml.cs
@@ -1,10 +1,24 @@
+using System;
 using Avalonia.Controls;
+using Avalonia.Controls.Shapes;
 using Avalonia.Markup.Xaml;
+using Avalonia.VisualTree;
 
 namespace Avalonia.Diagnostics.Views
 {
     internal class ControlDetailsView : UserControl
     {
+        private ThicknessEditor _borderArea;
+        private ThicknessEditor _paddingArea;
+        private Rectangle _horizontalSizeBegin;
+        private Rectangle _horizontalSizeEnd;
+        private Rectangle _verticalSizeBegin;
+        private Rectangle _verticalSizeEnd;
+        private Grid _layoutRoot;
+        private Border _horizontalSize;
+        private Border _verticalSize;
+        private Border _contentArea;
+
         public ControlDetailsView()
         {
             InitializeComponent();
@@ -13,6 +27,101 @@ namespace Avalonia.Diagnostics.Views
         private void InitializeComponent()
         {
             AvaloniaXamlLoader.Load(this);
+
+            _borderArea = this.FindControl<ThicknessEditor>("BorderArea");
+            _paddingArea = this.FindControl<ThicknessEditor>("PaddingArea");
+
+            _horizontalSizeBegin = this.FindControl<Rectangle>("HorizontalSizeBegin");
+            _horizontalSizeEnd = this.FindControl<Rectangle>("HorizontalSizeEnd");
+            _verticalSizeBegin = this.FindControl<Rectangle>("VerticalSizeBegin");
+            _verticalSizeEnd = this.FindControl<Rectangle>("VerticalSizeEnd");
+
+            _horizontalSize = this.FindControl<Border>("HorizontalSize");
+            _verticalSize = this.FindControl<Border>("VerticalSize");
+
+            _contentArea = this.FindControl<Border>("ContentArea");
+
+            _layoutRoot = this.FindControl<Grid>("LayoutRoot");
+
+            void SubscribeToBounds(Visual visual)
+            {
+                visual.GetPropertyChangedObservable(TransformedBoundsProperty)
+                    .Subscribe(UpdateSizeGuidelines);
+            }
+
+            SubscribeToBounds(_borderArea);
+            SubscribeToBounds(_paddingArea);
+            SubscribeToBounds(_contentArea);
+        }
+
+        private void UpdateSizeGuidelines(AvaloniaPropertyChangedEventArgs e)
+        {
+            void UpdateGuidelines(Visual area)
+            {
+                if (area.TransformedBounds is TransformedBounds bounds)
+                {
+                    // Horizontal guideline
+                    {
+                        var sizeArea = TranslateToRoot((_horizontalSize.TransformedBounds ?? default).Bounds.BottomLeft,
+                            _horizontalSize);
+
+                        var start = TranslateToRoot(bounds.Bounds.BottomLeft, area);
+
+                        SetPosition(_horizontalSizeBegin, start);
+
+                        var end = TranslateToRoot(bounds.Bounds.BottomRight, area);
+
+                        SetPosition(_horizontalSizeEnd, end.WithX(end.X - 1));
+
+                        var height = sizeArea.Y - start.Y + 2;
+
+                        _horizontalSizeBegin.Height = height;
+                        _horizontalSizeEnd.Height = height;
+                    }
+
+                    // Vertical guideline
+                    {
+                        var sizeArea = TranslateToRoot((_verticalSize.TransformedBounds ?? default).Bounds.TopRight, _verticalSize);
+
+                        var start = TranslateToRoot(bounds.Bounds.TopRight, area);
+
+                        SetPosition(_verticalSizeBegin, start);
+
+                        var end = TranslateToRoot(bounds.Bounds.BottomRight, area);
+
+                        SetPosition(_verticalSizeEnd, end.WithY(end.Y - 1));
+
+                        var width = sizeArea.X - start.X + 2;
+
+                        _verticalSizeBegin.Width = width;
+                        _verticalSizeEnd.Width = width;
+                    }
+                }
+            }
+
+            Point TranslateToRoot(Point point, IVisual from)
+            {
+                return from.TranslatePoint(point, _layoutRoot) ?? default;
+            }
+
+            static void SetPosition(Rectangle rect, Point start)
+            {
+                Canvas.SetLeft(rect, start.X);
+                Canvas.SetTop(rect, start.Y);
+            }
+
+            if (_borderArea.IsPresent)
+            {
+                UpdateGuidelines(_borderArea);
+            } 
+            else if (_paddingArea.IsPresent)
+            {
+                UpdateGuidelines(_paddingArea);
+            }
+            else
+            {
+                UpdateGuidelines(_contentArea);
+            }
         }
     }
 }
diff --git a/src/Avalonia.Diagnostics/Diagnostics/Views/ThicknessEditor.cs b/src/Avalonia.Diagnostics/Diagnostics/Views/ThicknessEditor.cs
index 58ea91c2fa..c7611c8c46 100644
--- a/src/Avalonia.Diagnostics/Diagnostics/Views/ThicknessEditor.cs
+++ b/src/Avalonia.Diagnostics/Diagnostics/Views/ThicknessEditor.cs
@@ -1,8 +1,21 @@
 using Avalonia.Controls;
 using Avalonia.Data;
+using Avalonia.Data.Converters;
+using Avalonia.Media;
 
 namespace Avalonia.Diagnostics.Views
 {
+    internal static class Converters
+    {
+        public static IValueConverter HasConstraintConverter =
+            new FuncValueConverter<object, TextDecorationCollection>(ConvertToDecoration);
+
+        private static TextDecorationCollection ConvertToDecoration(object arg)
+        {
+            return arg != null ? TextDecorations.Underline : null;
+        }
+    }
+
     internal class ThicknessEditor : ContentControl
     {
         public static readonly DirectProperty<ThicknessEditor, Thickness> ThicknessProperty =