Calculate HH:MM:SS Averages in MySQL

My movies database stores runtimes as a TIME value formatted as HH:MM:SS. Here's how to calculate the average runtime.

Option 1: Output formatted in HH:MM:SS

SELECT SEC_TO_TIME(AVG(TIME_TO_SEC(runtime))) AS average_runtime FROM movies;

Output:

+-----------------+
| average_runtime |
+-----------------+
| 01:44:12.7816   |
+-----------------+

Option 2: Get the average number of minutes of each runtime.

SELECT ROUND(AVG(TIME_TO_SEC(runtime) / 60), 2) AS avg_minutes FROM movies;

Output:

+-------------+
| avg_minutes |
+-------------+
|      104.21 |
+-------------+