Display posts word-count column in Wordpress post manage page: Full article at: http://imelgrat.me/wordpress/customize-wordpress-post-management-page/

show-wordcount.php

function post_word_count($post_id) {
    $content = get_post_field( 'post_content', $post_id );
    $word_count = str_word_count( strip_tags( strip_shortcodes($content) ) );
    return $word_count;
}

add_filter('manage_posts_columns', 'wordcount_column');
function wordcount_column($columns) {
    $columns['wordcount'] = 'Word count';
    return $columns;
}

add_action('manage_posts_custom_column',  'show_wordcount');
function show_wordcount($name) 
{
    global $post;
    switch ($name) 
	{
        case 'wordcount':
            $wordcount = post_word_count($post->ID);
            echo $wordcount;
    }
}