This article describes how to determine the current WordPress version of an installation.
The easiest way to determine the version of a WordPress installation is from the administration interface:
If the administration interface is unavailable or you cannot log in, you can still determine the WordPress version by checking the version.php file. To do this, follow these steps:
Locate the $wp_version variable. This variable's value contains the current WordPress version. For example, the following value indicates WordPress version 3.8.1 is installed:
$wp_version = '3.8.1';