Counting words in a post

How can I count words in a post? Something like the one displayed just below the post?

Can someone please show me the code for getting this. I have been searching everywhere.

How hard did you search? I searched Google for “wordpress count words in post” and found a function for it in the first result!

Put this in functions.php:

function prefix_wcount(){
    ob_start();
    the_content();
    $content = ob_get_clean();
    return sizeof(explode(" ", $content));
}

Then call it in the template like this:

<?php echo prefix_wcount(); ?>