diff --git a/defaults/main.yml b/defaults/main.yml
index 4c84514..6a5c6ca 100644
--- a/defaults/main.yml
+++ b/defaults/main.yml
@@ -3,6 +3,8 @@
 # IMPORTANT: the template will be used on a task that refers 'phpfpm_pools' inside a 'with_items' loop. So
 # the variables into the template are all 'item.XXX'
 #
+# PHPFPM calculator: https://spot13.com/pmcalculator/
+#
 phpfpm_service_enabled: True
 phpfpm_remove_php_module: True
 php_from_ppa: True