Index: default-constants.php
===================================================================
--- default-constants.php	(revision 27344)
+++ default-constants.php	(working copy)
@@ -87,6 +87,16 @@
 	define( 'DAY_IN_SECONDS',    24 * HOUR_IN_SECONDS   );
 	define( 'WEEK_IN_SECONDS',    7 * DAY_IN_SECONDS    );
 	define( 'YEAR_IN_SECONDS',  365 * DAY_IN_SECONDS    );
+
+	/* Human-readable byte units */
+	define( 'KB_IN_BYTES', 1024 );
+	define( 'MB_IN_BYTES', 1024 * KB_IN_BYTES );
+	define( 'GB_IN_BYTES', 1024 * MB_IN_BYTES );
+	define( 'TB_IN_BYTES', 1024 * GB_IN_BYTES );
+	define( 'PB_IN_BYTES', 1024 * TB_IN_BYTES );
+	define( 'EB_IN_BYTES', 1024 * PB_IN_BYTES );
+	define( 'ZB_IN_BYTES', 1024 * EB_IN_BYTES );
+	define( 'YB_IN_BYTES', 1024 * ZB_IN_BYTES );
 }
 
 /**