Get Page Depth - Wordpress

get_page_depth.php

/*
Plugin Name: get_page_depth
Author: Hameedullah Khan
Aurhor URI: http://hameedullah.com
 */

/*
 * get_page_depth
 * Gets the page depth, calls get_post on every iteration
 */
function get_page_depth( $id=0, $depth=0 ) {
    global $post;

    if ( $id == 0 ) 
        $id = $post->ID;

    $page = get_post( $id );
    if ( !$page->post_parent ) {
            // this page does not have any parent
            return $depth;
    }
    return get_page_depth( $page->post_parent, $depth+1 );
}