Has the Twelve Demon Moons power levels been given by the author? I was watching a YouTube video and the Youtuber said the ranking of the 9 Pillars has been given by the author. Apparently it would be, 


   9. Insect Pillar
 8. Serpent Pillar
 7. Mist Pillar
 6. Love Pillar
 5. Water Pillar
 4. Wind Pillar
 3. Flame Pillar
 2. Sound Pillar
 1. Stone Pillar 


How about the Twelve Demon Moons? Has the Twelve Demon Moons power levels been given by the author?
Their rankings are denoted by their numbers. Upper Moon 1 through 6 are the strongest 6 after Muzan arranged in the order of their numbers, then lower 6 stand in a similar fashion. 

Here's some info from the manga:


   Upper moon 1 was annoyed that Upper moon 3 Akaza did not abide to the hierarchy of Upper moons. He suggested that if this bothers him so much, he can apply for a Blood battle against Upper Moon 2 to swap places implying the hierarchy is based on battle strength


This is what we can assume given the latest chapters:


  There are some demons with the potential to be one of the moons. As we see that Upper moon 6 (Daki and Gyutaro) and Upper moon 4 (Hantengu) were replaced in a matter of days following their deaths.