To give WordPress enough resources to work properly with a complex theme, all the plugins and many visitors, it is highly recommended to add this to the wp-config.php file:

/* Ensure WordPress has enough resources to work with */
define( 'WP_MEMORY_LIMIT', '64M' );
define( 'WP_MAX_MEMORY_LIMIT', '256M' );

The above code allows WordPress to use up to that limit amount if it needs to. If your site is really resource intensive and becomes slow or has some issues when there are a lot of visitors, it might be worthwhile to try and increase the WP_MEMORY_LIMIT even more.

This is done as standard for all sites that we build at Your Easy Web Solutions to ensure that they run smoothly.