Welcome to what Anime watchers have to deal with, Common length is 12-13, there'll be some shows that go on to 24-26, and very rarely way past that like SAO Alicization is said to be around 50, but the standard is 12, it's so annoying, I'd be much happier if 24 was the common instead of 12.....12 just feels so.....short....
---
PSN: http://card.psnprofiles.com/1/TwilightGundam01.png
Fate/Grand Order EN: 866,770,168. Fate/Grand Order JP: 688,739,705.