How Many Levels of Sub-Categories Does WordPress Support?

One TaxoPress user asked us if there is a limit to the number of sub-categories they can create on their WordPress site.

No, there is no technical limit to how deep your nested categories can go. In the image below, I’ve created 10 levels of categories:

Adding new WordPress subcategories

You can keep adding sub-category levels as deep as you wish. The main limitation to consider will be the WordPress admin area which will start to look strained. In the image below, I’ve added twenty levels. When I go to add “Level 21”, the “Parent Category” dropdown appears to be broken.

Add New Category for WordPress subcategories

In the next image, you can see how those extra levels appear on the main “Categories” screen. Each one is only displayed after a long row of hyphens.

Categories screen for WordPress subcategories

And when you try to add a category to a post, you may find that the lower levels are not easily visible inside the metabox.

Metabox for WordPress sub-categories

The reason that WordPress allows you to have an unlimited number of sub-categories is that these are simple database entries. The sub-categories are controlled by the parent column in the wp_term_taxonomy table. Adding more sub-categories will not slow your site down at all.

Database table for WordPress subcategories

Finally, I’ll note that you can turn add multiple levels to any WordPress taxonomy. Go to the “Taxonomies” screen in TaxoPress. When you click “Edit”, you’ll be able to change the settings for each taxonomy. You can control whether the taxonomy is organized in parent-child relationships.

If you do want to go many levels deep with sub-categories, it might be best to do it with an internal taxonomy where your regular user can learn to navigate the WordPress quirks mentioned in this post. You can use these categories to connect any post type, including Pages.