functions.php

<?php

function be_equal_sized_menu_items( $classes, $item, $args ) {

// Only run on the header menu
if( ‘top_menu’ !== $args->theme_location )
return $classes;

// Only run on top level menu items
if( $item->menu_item_parent )
return $classes;

// Grab all menu items

// Added lines
$menu_name = ‘top_menu’;

if ( ( $locations = get_nav_menu_locations() ) && isset( $locations[ $menu_name ] ) ) {
$menu = wp_get_nav_menu_object( $locations[ $menu_name ] );
}

// Changed line
$menu_items = wp_get_nav_menu_items($menu->term_id);

// Remove submenu items
foreach( $menu_items as $i => $menu_item )
if( $menu_item->menu_item_parent )
unset( $menu_items[$i] );

// Count all top level items, and add as a class
$classes[] = ‘count-‘ . count( $menu_items );
return $classes;
}