diff --git a/launcher/minecraft/World.cpp b/launcher/minecraft/World.cpp
index fc67fbb13..8ae097bad 100644
--- a/launcher/minecraft/World.cpp
+++ b/launcher/minecraft/World.cpp
@@ -198,22 +198,6 @@ bool putLevelDatDataToFS(const QFileInfo& file, QByteArray& data)
     return f.commit();
 }
 
-int64_t calculateWorldSize(const QFileInfo& file)
-{
-    if (file.isFile() && file.suffix() == "zip") {
-        return file.size();
-    } else if (file.isDir()) {
-        QDirIterator it(file.absoluteFilePath(), QDir::Files, QDirIterator::Subdirectories);
-        int64_t total = 0;
-        while (it.hasNext()) {
-            it.next();
-            total += it.fileInfo().size();
-        }
-        return total;
-    }
-    return -1;
-}
-
 World::World(const QFileInfo& file)
 {
     repath(file);
@@ -223,7 +207,6 @@ void World::repath(const QFileInfo& file)
 {
     m_containerFile = file;
     m_folderName = file.fileName();
-    m_size = calculateWorldSize(file);
     if (file.isFile() && file.suffix() == "zip") {
         m_iconFile = QString();
         readFromZip(file);
@@ -531,3 +514,8 @@ bool World::isMoreThanOneHardLink() const
     }
     return FS::hardLinkCount(m_containerFile.absoluteFilePath()) > 1;
 }
+
+void World::setSize(int64_t size)
+{
+    m_size = size;
+}
diff --git a/launcher/minecraft/World.h b/launcher/minecraft/World.h
index 6a4e1f092..34d418e79 100644
--- a/launcher/minecraft/World.h
+++ b/launcher/minecraft/World.h
@@ -54,6 +54,8 @@ class World {
     bool rename(const QString& to);
     bool install(const QString& to, const QString& name = QString());
 
+    void setSize(int64_t size);
+
     // WEAK compare operator - used for replacing worlds
     bool operator==(const World& other) const;
 
diff --git a/launcher/minecraft/WorldList.cpp b/launcher/minecraft/WorldList.cpp
index f06eddb66..5f192740e 100644
--- a/launcher/minecraft/WorldList.cpp
+++ b/launcher/minecraft/WorldList.cpp
@@ -37,13 +37,14 @@
 
 #include <FileSystem.h>
 #include <QDebug>
+#include <QDirIterator>
 #include <QFileSystemWatcher>
 #include <QMimeData>
 #include <QString>
+#include <QThreadPool>
 #include <QUrl>
 #include <QUuid>
 #include <Qt>
-#include "Application.h"
 
 WorldList::WorldList(const QString& dir, BaseInstance* instance) : QAbstractListModel(), m_instance(instance), m_dir(dir)
 {
@@ -103,6 +104,7 @@ bool WorldList::update()
     beginResetModel();
     m_worlds.swap(newWorlds);
     endResetModel();
+    loadWorldsAsync();
     return true;
 }
 
@@ -416,4 +418,44 @@ bool WorldList::dropMimeData(const QMimeData* data,
     return false;
 }
 
+int64_t calculateWorldSize(const QFileInfo& file)
+{
+    if (file.isFile() && file.suffix() == "zip") {
+        return file.size();
+    } else if (file.isDir()) {
+        QDirIterator it(file.absoluteFilePath(), QDir::Files, QDirIterator::Subdirectories);
+        int64_t total = 0;
+        while (it.hasNext()) {
+            it.next();
+            total += it.fileInfo().size();
+        }
+        return total;
+    }
+    return -1;
+}
+
+void WorldList::loadWorldsAsync()
+{
+    for (int i = 0; i < m_worlds.size(); ++i) {
+        auto file = m_worlds.at(i).container();
+        int row = i;
+        QThreadPool::globalInstance()->start([this, file, row]() mutable {
+            auto size = calculateWorldSize(file);
+
+            QMetaObject::invokeMethod(
+                this,
+                [this, size, row, file]() {
+                    if (row < m_worlds.size() && m_worlds[row].container() == file) {
+                        m_worlds[row].setSize(size);
+
+                        // Notify views
+                        QModelIndex modelIndex = index(row);
+                        emit dataChanged(modelIndex, modelIndex, { SizeRole });
+                    }
+                },
+                Qt::QueuedConnection);
+        });
+    }
+}
+
 #include "WorldList.moc"
diff --git a/launcher/minecraft/WorldList.h b/launcher/minecraft/WorldList.h
index 45e2eecac..93fecf1f5 100644
--- a/launcher/minecraft/WorldList.h
+++ b/launcher/minecraft/WorldList.h
@@ -86,6 +86,7 @@ class WorldList : public QAbstractListModel {
 
    private slots:
     void directoryChanged(QString path);
+    void loadWorldsAsync();
 
    signals:
     void changed();