diff --git a/Ooui.Forms/Extensions/FontExtensions.cs b/Ooui.Forms/Extensions/FontExtensions.cs
index 765ee02..310ece6 100644
--- a/Ooui.Forms/Extensions/FontExtensions.cs
+++ b/Ooui.Forms/Extensions/FontExtensions.cs
@@ -5,8 +5,55 @@ namespace Ooui.Forms.Extensions
 {
     public static class FontExtensions
     {
-        public static void SetStyleFont (this View view, Style style)
+        public static void SetStyleFont (this View view, string family, double size, FontAttributes attrs, Style style)
         {
+#pragma warning disable RECS0018 // Comparison of floating point numbers with equality operator
+            if (size == 14.0) {
+                style.FontSize = null;
+            }
+            else {
+                style.FontSize = size;
+            }
+#pragma warning restore RECS0018 // Comparison of floating point numbers with equality operator
+
+            if (string.IsNullOrEmpty (family)) {
+                style.FontFamily = null;
+            }
+            else {
+                style.FontFamily = family;
+            }
+
+            if (attrs.HasFlag (FontAttributes.Bold)) {
+                style.FontWeight = "bold";
+            }
+            else {
+                style.FontWeight = null;
+            }
+
+            if (attrs.HasFlag (FontAttributes.Italic)) {
+                style.FontStyle = "italic";
+            }
+            else {
+                style.FontStyle = null;
+            }
+        }
+
+        public static Size MeasureSize (this string text, string fontFamily, double fontSize, FontAttributes fontAttrs)
+        {
+            if (string.IsNullOrEmpty (text))
+                return Size.Zero;
+
+            var fontHeight = fontSize;
+            var charWidth = fontSize * 0.5;
+
+            var width = text.Length * charWidth;
+
+            return new Size (width, fontHeight);
+        }
+
+        public static Size MeasureSize (this string text, Style style)
+        {
+            return MeasureSize (text, "", 14, FontAttributes.None);
         }
 
         public static string ToOouiTextAlign (this TextAlignment align)
@@ -22,17 +69,5 @@ namespace Ooui.Forms.Extensions
             }
         }
 
-        public static Size MeasureSize (this string text, Style style)
-        {
-            if (string.IsNullOrEmpty (text))
-                return Size.Zero;
-
-            var fontHeight = 16.0;
-            var charWidth = 8.0;
-
-            var width = text.Length * charWidth;
-
-            return new Size (width, fontHeight);
-        }
     }
 }
diff --git a/Ooui.Forms/Renderers/ButtonRenderer.cs b/Ooui.Forms/Renderers/ButtonRenderer.cs
index 751e6c7..727d835 100644
--- a/Ooui.Forms/Renderers/ButtonRenderer.cs
+++ b/Ooui.Forms/Renderers/ButtonRenderer.cs
@@ -12,6 +12,13 @@ namespace Ooui.Forms.Renderers
         Ooui.Color _buttonTextColorDefaultHighlighted;
         Ooui.Color _buttonTextColorDefaultNormal;
 
+        public override SizeRequest GetDesiredSize (double widthConstraint, double heightConstraint)
+        {
+            var size = Element.Text.MeasureSize (Element.FontFamily, Element.FontSize, Element.FontAttributes);
+            size = new Size (size.Width, size.Height * 1.428 + 14);
+            return new SizeRequest (size, size);
+        }
+
         protected override void Dispose (bool disposing)
         {
             if (Control != null) {
@@ -31,6 +38,8 @@ namespace Ooui.Forms.Renderers
 
                     Debug.Assert (Control != null, "Control != null");
 
+                    Control.ClassName = "btn btn-primary";
+
                     _buttonTextColorDefaultNormal = Ooui.Colors.Black;
                     _buttonTextColorDefaultHighlighted = Ooui.Colors.Black;
                     _buttonTextColorDefaultDisabled = Ooui.Colors.Black;
@@ -98,7 +107,7 @@ namespace Ooui.Forms.Renderers
 
         void UpdateFont ()
         {
-            Element.SetStyleFont (Control.Style);
+            Element.SetStyleFont (Element.FontFamily, Element.FontSize, Element.FontAttributes, Control.Style);
         }
 
         void UpdateImage ()
@@ -141,14 +150,10 @@ namespace Ooui.Forms.Renderers
         void UpdateTextColor ()
         {
             if (Element.TextColor == Xamarin.Forms.Color.Default) {
-                Control.Style.Color = _buttonTextColorDefaultNormal;
-                Control.Style.Color = _buttonTextColorDefaultHighlighted;
-                Control.Style.Color = _buttonTextColorDefaultDisabled;
+                Control.Style.Color = null;
             }
             else {
                 Control.Style.Color = Element.TextColor.ToOouiColor ();
-                Control.Style.Color = Element.TextColor.ToOouiColor ();
-                Control.Style.Color = _buttonTextColorDefaultDisabled;
             }
         }
     }
diff --git a/Ooui.Forms/Renderers/EntryRenderer.cs b/Ooui.Forms/Renderers/EntryRenderer.cs
index d48f78e..e72843d 100644
--- a/Ooui.Forms/Renderers/EntryRenderer.cs
+++ b/Ooui.Forms/Renderers/EntryRenderer.cs
@@ -140,7 +140,7 @@ namespace Ooui.Forms.Renderers
                 initialSize = testString.MeasureSize (Control.Style);
             }
 
-            Element.SetStyleFont (Control.Style);
+            Element.SetStyleFont (Element.FontFamily, Element.FontSize, Element.FontAttributes, Control.Style);
         }
 
         void UpdateKeyboard ()
diff --git a/Ooui.Forms/Renderers/LabelRenderer.cs b/Ooui.Forms/Renderers/LabelRenderer.cs
index 402563e..6a6104d 100644
--- a/Ooui.Forms/Renderers/LabelRenderer.cs
+++ b/Ooui.Forms/Renderers/LabelRenderer.cs
@@ -17,8 +17,8 @@ namespace Ooui.Forms.Renderers
         public override SizeRequest GetDesiredSize (double widthConstraint, double heightConstraint)
         {
             if (!_perfectSizeValid) {
-                _perfectSize = base.GetDesiredSize (double.PositiveInfinity, double.PositiveInfinity);
-                _perfectSize.Minimum = new Size (Math.Min (10, _perfectSize.Request.Width), _perfectSize.Request.Height);
+                var size = Element.Text.MeasureSize (Element.FontFamily, Element.FontSize, Element.FontAttributes);
+                _perfectSize = new SizeRequest (size, size);
                 _perfectSizeValid = true;
             }
 
@@ -157,7 +157,7 @@ namespace Ooui.Forms.Renderers
                 return;
             _perfectSizeValid = false;
 
-            Element.SetStyleFont (Control.Style);
+            Element.SetStyleFont (Element.FontFamily, Element.FontSize, Element.FontAttributes, Control.Style);
         }
 
         void UpdateTextColor ()
diff --git a/Ooui/Style.cs b/Ooui/Style.cs
index cec8577..06b6149 100644
--- a/Ooui/Style.cs
+++ b/Ooui/Style.cs
@@ -180,7 +180,7 @@ namespace Ooui
 
         public Value FontSize {
             get => this["font-size"];
-            set => this["font-size"] = value;
+            set => this["font-size"] = AddNumberUnits (value, "px");
         }
 
         public Value FontStyle {
diff --git a/Samples/ButtonXamlPage.xaml b/Samples/ButtonXamlPage.xaml
old mode 100755
new mode 100644
index 02012d6..9fafa5f
--- a/Samples/ButtonXamlPage.xaml
+++ b/Samples/ButtonXamlPage.xaml
@@ -1,4 +1,4 @@
-<?xml version="1.0" encoding="utf-8" ?>
+<?xml version="1.0" encoding="utf-8" ?>
 <ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
              xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
              x:Class="ButtonXaml.ButtonXamlPage">
@@ -7,7 +7,6 @@
         <Label Text="Welcome to Xamarin.Forms!"/>
         <Label x:Name="LabelCount" Text="Click Count: 0"/>
         <Button Text="Tap for click count!"
-                HeightRequest="30"
                 Clicked="OnButtonClicked" />
     </StackLayout>
 </ContentPage>
diff --git a/Samples/DisplayAlertPage.xaml b/Samples/DisplayAlertPage.xaml
index 039fe09..8f3c57f 100644
--- a/Samples/DisplayAlertPage.xaml
+++ b/Samples/DisplayAlertPage.xaml
@@ -6,7 +6,6 @@
         <StackLayout>
             <Label Text="Welcome to DisplayAlert Sample!" />
             <Button Text="Tap for Display Alert"
-                    HeightRequest="30"
                     Clicked="OnButtonClicked" />
         </StackLayout>
     </ContentPage.Content>