Version: 2017.2
public static int loadedSceneCount ;


The number of loaded Scenes.

Returns the current number of loaded Scenes in the Editor.

using UnityEditor;
using UnityEditor.SceneManagement;

public class Example { // adds a custom menu item which displays the number of open Scenes in a Dialogue Box [MenuItem("SceneExample/Number Of Scenes")] public static void NumberOfScenes() { EditorUtility.DisplayDialog("Number of loaded Scenes:", EditorSceneManager.loadedSceneCount.ToString(), "Ok"); } }