get_blog_count() │ WP 3.0.0

Gets the number of active sites on the installation.

The count is cached and updated twice daily. This is not a live count.

No Hooks.

Returns

Int. Number of active sites on the network.

Usage

get_blog_count( $network_id );
$network_id(int|null)
ID of the network.
Default: current network

Changelog

Since 3.0.0 Introduced.
Since 3.7.0 The $network_id parameter has been deprecated.
Since 4.8.0 The $network_id parameter is now being used.

get_blog_count() code WP 7.0

wp-includes/ms-functions.php 
function get_blog_count( $network_id = null ) {
	return get_network_option( $network_id, 'blog_count' );
}