function feed_subscribers(){
$feed_url = 'http://feeds.feedburner.com/yourname';
$count = get_transient('feed_count');
if ($count != false) return $count;
$count = 0;
$data  = wp_remote_get('http://feedburner.google.com/api/awareness/1.0/GetFeedData?uri='.$feed_url.'');
if (is_wp_error($data)) {
return 'error';
}else{
$body = wp_remote_retrieve_body($data);
$xml = new SimpleXMLElement($body);
$status = $xml->attributes();
if ($status == 'ok') {
$count = $xml->feed->entry->attributes()->circulation;
} else {
$count = 300; // fallback number
}
}
set_transient('feed_count', $count, 60*60*24); // 24 hour cache
echo $count;
}

Then add this to your WordPress theme in the location you wish to display the RSS feed subscriber count.


<? feed_subscribers(); ?>

Get Feedburner Count Using Get_Transient and Wp_Remote_Get 

wordpress

PHP