diff --git a/Terminal.Gui/Views/TreeView/TreeViewT.cs b/Terminal.Gui/Views/TreeView/TreeViewT.cs
index aeae194acf..2d745289a8 100644
--- a/Terminal.Gui/Views/TreeView/TreeViewT.cs
+++ b/Terminal.Gui/Views/TreeView/TreeViewT.cs
@@ -686,11 +686,7 @@ private void UpdateContentSize ()
 
         try
         {
-            IReadOnlyCollection<Branch<T>> map = BuildLineMap ();
-            int width = map.Count > 0 ? map.Max (b => b.GetWidth ()) : 0;
-            int height = map.Count;
-
-            SetContentSize (new Size (width, height));
+            SetContentSize (GetSize ());
         }
         finally
         {
@@ -698,6 +694,18 @@ private void UpdateContentSize ()
         }
     }
 
+    /// <summary>
+    ///     Calculates the logical size of the tree based on currently expanded branches. The width is the maximum width of
+    ///     all visible branches, and the height is the total number of visible branches.
+    /// </summary>
+    /// <returns></returns>
+    public Size GetSize ()
+    {
+        IReadOnlyCollection<Branch<T>> map = BuildLineMap ();
+
+        return new Size (map.Count > 0 ? map.Max (b => b.GetWidth ()) : 0, map.Count);
+    }
+
     /// <inheritdoc/>
     protected override void OnViewportChanged (DrawEventArgs e)
     {