diff --git a/src/Models/S3File.php b/src/Models/S3File.php
index fe99937..adee382 100644
--- a/src/Models/S3File.php
+++ b/src/Models/S3File.php
@@ -17,10 +17,7 @@ class S3File extends File
 
     public function calculateFilesize(): int
     {
-        return $this->getS3Client()->headObject([
-            'Bucket' => $this->getBucket(),
-            'Key'    => $this->getKey()
-        ])->get('ContentLength');
+        return $this->getReadableStream()->getSize();
     }
 
     public function setS3Client(S3Client $client): self
@@ -39,16 +36,6 @@ public function getS3Client(): S3Client
         return $this->client;
     }
 
-    public function getBucket(): string
-    {
-        return parse_url($this->getSource(), PHP_URL_HOST);
-    }
-
-    public function getKey(): string
-    {
-        return ltrim(parse_url($this->getSource(), PHP_URL_PATH), "/");
-    }
-
     protected function buildReadableStream(): StreamInterface
     {
         $this->getS3Client()->registerStreamWrapper();