Display the total number of Child Categories Count of a Parent by ID

                        
                          <?php
// Get the child categories of the parent category with ID 288
$child_categories = get_categories(array(
	'child_of' => 288,
	'hide_empty' => false, // Change to true if you only want to count non-empty categories
));

// Count the number of child categories
$total_child_categories = count($child_categories);

// Display the total number of child categories
echo $total_child_categories;
?>