nanbaocprison: this images says alot about dabis age

This!!!!! is very helpful. So Dabi is canonly in his early twenties. I checked the Japanese version and it says “around 20″.

With this in mind, it is definitely possible that Dabi is the 3rd child (who according to my math is 18-20). Him being the 1st child (assuming he’s under 25) isn’t ruled out either. We just know he is in his early twenties.