Found this -- hope it helps
Create a new function in the Functions.php as follows
function Get_Post_Number($postID){
$temp_query = $wp_query;
$postNumberQuery = new WP_Query('orderby=date&order=<strong>DESC</strong>&posts_per_page=-1');
$counter = 1;
$postCount = 0;
if($postNumberQuery->have_posts()) :
while ($postNumberQuery->have_posts()) : $postNumberQuery->the_post();
if ($postID == get_the_ID()){
$postCount = $counter;
} else {
$counter++;
}
endwhile; endif;
wp_reset_query();
$wp_query = $temp_query;
return $postCount;
}
(Change above bolded ASC to DESC if you want to see the numbers in reverse (latest post as highest number).)
Then in the index.php (or page template), anywhere after "<?php if (have_posts()) : while (have_posts()) : the_post(); ?>" just add the following code wherever you want the Post # to show up.
<?php $currentID = get_the_ID(); ?>
<?php $currentNumber = Get_Post_Number($currentID); ?>
<?php echo $currentNumber; ?>
Good luck!!!