Board Thread:Support Requests - Designing Your Wiki/@comment-44616326-20200318004003/@comment-9605025-20200318030543

To get the number of pages in a category, you can use the PAGESINCATEGORY magic word. To perform calculations, you can use the #expr parser function.

Note that the PAGESINCATEGORY magic word is considered an expensive function. This means that it counts towards a page's expensive function limit. If a particular instance of an expensive function would cause the page to exceed this limit, that particular instance is ignored. For example, let's say the limit is 10 (the actual limit is higher) but you use PAGESINCATEGORY 12 times. The first 10 uses of the magic word will work as expected. The last 2 uses will not. - Edit:

PAGESINCATEGORY is not the only expensive function and the limit is shared by all expensive functions on the page.