diff --git a/src/uploader/upload.js b/src/uploader/upload.js
index 4cfe212..2efd4da 100644
--- a/src/uploader/upload.js
+++ b/src/uploader/upload.js
@@ -48,7 +48,7 @@ export default function upload(options) {
     xhr.upload.addEventListener('progress', function (evt) {
         if(evt.total == 0) return;
 
-        const percent = Math.ceil(evt.loaded / evt.total) * 100;
+        const percent = Math.ceil(evt.loaded / evt.total * 100);
 
         onProgress(file, percent);
     }, false);