diff --git a/public/php/functions.php b/public/php/functions.php
index 5af92a4..5bd3c61 100644
--- a/public/php/functions.php
+++ b/public/php/functions.php
@@ -23,7 +23,7 @@
       $drive->spaceFree = disk_free_space($drive->location);
       $drive->spaceTotal = disk_total_space($drive->location);
       $drive->spaceUsed = getDifference(
-        $drive->spaceFree, $drive->spaceTotal);
+        $drive->spaceTotal, $drive->spaceFree);
       $drive->spacePercentageUsed = getPercentageUsed(
         $drive->spaceTotal, $drive->spaceUsed);
     }