diff --git a/.changes/nsis-slow-resources-installation.md b/.changes/nsis-slow-resources-installation.md
new file mode 100644
index 000000000..486227050
--- /dev/null
+++ b/.changes/nsis-slow-resources-installation.md
@@ -0,0 +1,7 @@
+---
+"@tauri-apps/cli": patch:bug
+"tauri-cli": patch:bug
+"tauri-bundler": patch:bug
+---
+
+Fixes an issue in the NSIS installer which caused the installation to take much longer than expected when many `resources` were added to the bundle.
diff --git a/tooling/bundler/src/bundle/windows/nsis.rs b/tooling/bundler/src/bundle/windows/nsis.rs
index b0711b31e..afa148ddb 100644
--- a/tooling/bundler/src/bundle/windows/nsis.rs
+++ b/tooling/bundler/src/bundle/windows/nsis.rs
@@ -290,23 +290,27 @@ fn build_nsis_app_installer(
     .iter()
     .find(|bin| bin.main())
     .ok_or_else(|| anyhow::anyhow!("Failed to get main binary"))?;
+  let main_binary_path = settings.binary_path(main_binary).with_extension("exe");
   data.insert(
     "main_binary_name",
     to_json(main_binary.name().replace(".exe", "")),
   );
-  data.insert(
-    "main_binary_path",
-    to_json(settings.binary_path(main_binary).with_extension("exe")),
-  );
+  data.insert("main_binary_path", to_json(&main_binary_path));
 
   let out_file = "nsis-output.exe";
   data.insert("out_file", to_json(out_file));
 
   let resources = generate_resource_data(settings)?;
-  data.insert("resources", to_json(resources));
+  let resources_dirs =
+    std::collections::HashSet::<PathBuf>::from_iter(resources.values().map(|r| r.0.to_owned()));
+  data.insert("resources_dirs", to_json(resources_dirs));
+  data.insert("resources", to_json(&resources));
 
   let binaries = generate_binaries_data(settings)?;
-  data.insert("binaries", to_json(binaries));
+  data.insert("binaries", to_json(&binaries));
+
+  let estimated_size = generate_estimated_size(&main_binary_path, &binaries, &resources)?;
+  data.insert("estimated_size", to_json(estimated_size));
 
   let silent_webview2_install = if let WebviewInstallMode::DownloadBootstrapper { silent }
   | WebviewInstallMode::EmbedBootstrapper { silent }
@@ -552,6 +556,24 @@ fn generate_binaries_data(settings: &Settings) -> crate::Result<BinariesMap> {
   Ok(binaries)
 }
 
+fn generate_estimated_size(
+  main: &Path,
+  binaries: &BinariesMap,
+  resources: &ResourcesMap,
+) -> crate::Result<String> {
+  use std::fs::metadata;
+
+  let mut size = metadata(main)?.len();
+
+  for k in binaries.keys().chain(resources.keys()) {
+    size += metadata(k)?.len();
+  }
+
+  size /= 1000;
+
+  Ok(format!("{size:#08x}"))
+}
+
 fn get_lang_data(
   lang: &str,
   custom_lang_files: Option<&HashMap<String, PathBuf>>,
diff --git a/tooling/bundler/src/bundle/windows/templates/installer.nsi b/tooling/bundler/src/bundle/windows/templates/installer.nsi
index 45e63acc0..d19bce14e 100644
--- a/tooling/bundler/src/bundle/windows/templates/installer.nsi
+++ b/tooling/bundler/src/bundle/windows/templates/installer.nsi
@@ -40,6 +40,7 @@ ${StrLoc}
 !define UNINSTKEY "Software\Microsoft\Windows\CurrentVersion\Uninstall\${PRODUCTNAME}"
 !define MANUPRODUCTKEY "Software\${MANUFACTURER}\${PRODUCTNAME}"
 !define UNINSTALLERSIGNCOMMAND "{{uninstaller_sign_cmd}}"
+!define ESTIMATEDSIZE "{{estimated_size}}"
 
 Name "${PRODUCTNAME}"
 BrandingText "${COPYRIGHT}"
@@ -522,31 +523,26 @@ SectionEnd
   app_check_done:
 !macroend
 
-Var AppSize
 Section Install
   SetOutPath $INSTDIR
-  StrCpy $AppSize 0
 
   !insertmacro CheckIfAppIsRunning
 
   ; Copy main executable
   File "${MAINBINARYSRCPATH}"
-  ${GetSize} "$INSTDIR" "/M=${MAINBINARYNAME}.exe /S=0B" $0 $1 $2
-  IntOp $AppSize $AppSize + $0
 
   ; Copy resources
+  {{#each resources_dirs}}
+    ; `\\` is not a typo.
+    CreateDirectory "$INSTDIR\\{{this}}"
+  {{/each}}
   {{#each resources}}
-    CreateDirectory "$INSTDIR\\{{this.[0]}}"
     File /a "/oname={{this.[1]}}" "{{@key}}"
-    ${GetSize} "$INSTDIR" "/M={{this.[1]}} /S=0B" $0 $1 $2
-    IntOp $AppSize $AppSize + $0
   {{/each}}
 
   ; Copy external binaries
   {{#each binaries}}
     File /a "/oname={{this}}" "{{@key}}"
-    ${GetSize} "$INSTDIR" "/M={{this}} /S=0B" $0 $1 $2
-    IntOp $AppSize $AppSize + $0
   {{/each}}
 
   ; Create uninstaller
@@ -570,9 +566,7 @@ Section Install
   WriteRegStr SHCTX "${UNINSTKEY}" "UninstallString" "$\"$INSTDIR\uninstall.exe$\""
   WriteRegDWORD SHCTX "${UNINSTKEY}" "NoModify" "1"
   WriteRegDWORD SHCTX "${UNINSTKEY}" "NoRepair" "1"
-  IntOp $AppSize $AppSize / 1000
-  IntFmt $AppSize "0x%08X" $AppSize
-  WriteRegDWORD SHCTX "${UNINSTKEY}" "EstimatedSize" "$AppSize"
+  WriteRegDWORD SHCTX "${UNINSTKEY}" "EstimatedSize" "${ESTIMATEDSIZE}"
 
   ; Create start menu shortcut (GUI)
   !insertmacro MUI_STARTMENU_WRITE_BEGIN Application