diff --git a/Source/Core/DiscIO/Filesystem.cpp b/Source/Core/DiscIO/Filesystem.cpp
index 9e5336db5d..68a7decb3e 100644
--- a/Source/Core/DiscIO/Filesystem.cpp
+++ b/Source/Core/DiscIO/Filesystem.cpp
@@ -8,6 +8,19 @@ namespace DiscIO
 {
 FileInfo::~FileInfo() = default;
 
+u64 FileInfo::GetTotalSize() const
+{
+  if (!IsDirectory())
+    return GetSize();
+
+  u64 size = 0;
+
+  for (const auto& entry : *this)
+    size += entry.GetTotalSize();
+
+  return size;
+}
+
 FileSystem::~FileSystem() = default;
 
-}  // namespace
+}  // namespace DiscIO
diff --git a/Source/Core/DiscIO/Filesystem.h b/Source/Core/DiscIO/Filesystem.h
index 37dc7f9b7e..ad631b078b 100644
--- a/Source/Core/DiscIO/Filesystem.h
+++ b/Source/Core/DiscIO/Filesystem.h
@@ -86,6 +86,8 @@ public:
   // The size of a file.
   // Not guaranteed to return a meaningful value for directories.
   virtual u32 GetSize() const = 0;
+  // For a file, returns its size. For a directory, returns the total size of its contents.
+  u64 GetTotalSize() const;
   virtual bool IsDirectory() const = 0;
   // The number of files and directories in a directory, including those in subdirectories.
   // Not guaranteed to return a meaningful value for files.
@@ -124,4 +126,4 @@ public:
 // because it will check IsValid for you, will automatically pick the right type of filesystem,
 // and will cache the filesystem in case it's needed again later.
 
-}  // namespace
+}  // namespace DiscIO
diff --git a/Source/Core/DolphinQt2/Config/FilesystemWidget.cpp b/Source/Core/DolphinQt2/Config/FilesystemWidget.cpp
index bfae5b78df..165ef0fd09 100644
--- a/Source/Core/DolphinQt2/Config/FilesystemWidget.cpp
+++ b/Source/Core/DolphinQt2/Config/FilesystemWidget.cpp
@@ -25,6 +25,8 @@
 #include "DolphinQt2/QtUtils/ActionHelper.h"
 #include "DolphinQt2/Resources.h"
 
+#include "UICommon/UICommon.h"
+
 constexpr int ENTRY_PARTITION = Qt::UserRole;
 constexpr int ENTRY_NAME = Qt::UserRole + 1;
 constexpr int ENTRY_TYPE = Qt::UserRole + 2;
@@ -52,11 +54,18 @@ void FilesystemWidget::CreateWidgets()
 {
   auto* layout = new QVBoxLayout;
 
-  m_tree_model = new QStandardItemModel(0, 1);
+  m_tree_model = new QStandardItemModel(0, 2);
+  m_tree_model->setHorizontalHeaderLabels({tr("Name"), tr("Size")});
+
   m_tree_view = new QTreeView(this);
   m_tree_view->setModel(m_tree_model);
   m_tree_view->setContextMenuPolicy(Qt::CustomContextMenu);
-  m_tree_view->header()->hide();
+
+  auto* header = m_tree_view->header();
+
+  header->setSectionResizeMode(0, QHeaderView::Stretch);
+  header->setSectionResizeMode(1, QHeaderView::ResizeToContents);
+  header->setStretchLastSection(false);
 
 // Windows: Set style to (old) windows, which draws branch lines
 #ifdef _WIN32
@@ -132,7 +141,14 @@ void FilesystemWidget::PopulateDirectory(int partition_id, QStandardItem* root,
     item->setData(QString::fromStdString(info.GetPath()), ENTRY_NAME);
     item->setData(QVariant::fromValue(info.IsDirectory() ? EntryType::Dir : EntryType::File),
                   ENTRY_TYPE);
-    root->appendRow(item);
+
+    const auto size = info.GetTotalSize();
+
+    auto* size_item = new QStandardItem(QString::fromStdString(UICommon::FormatSize(size)));
+    size_item->setTextAlignment(Qt::AlignRight);
+    size_item->setEditable(false);
+
+    root->appendRow({item, size_item});
   }
 }