diff --git a/advanced/learning_processes.md b/advanced/learning_processes.md
index aa66f0b..f5b46d3 100644
--- a/advanced/learning_processes.md
+++ b/advanced/learning_processes.md
@@ -345,6 +345,8 @@ You can tell because they are at `0`.
 The **nice** scale goes from `-20` being not-at-all-nice to `20` being super friendly towards other processes.
 The nicer a process the less aggressive it will be when demanding CPU time.
 
+The formula for the **priority** is PR=20+NI where NI is a value between -20 and 19.
+
 ### Nice
 
 Depending on your system a new process will get a specific nice value.