You mean like:
<?php
$args=array(
'post_type' => 'post',
'post_status' => 'publish',
'posts_per_page' => -1,
'caller_get_posts'=> 1
);
$my_query = null;
$my_query = new WP_Query($args);
if( $my_query->have_posts() ) {
while ($my_query->have_posts()) : $my_query->the_post(); ?>
<p><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title_attribute(); ?>"><?php the_title(); ?></a></p>
<?php
echo 'length of post content is '. strlen( $my_query->post->post_content);
endwhile;
}
wp_reset_query(); // Restore global post data stomped by the_post().
?>
Related:
http://php.net/manual/en/function.strlen.php
