It really varies. It is different between dragons and different between their own growth spurt cycles. I would start recording weight in grams every day so you have plot points then graph it out. That will allow you to watch trends over time and if the trend is steadily upward then that's a good sign. In my opinion it's better to watch trends than worry about specific numbers or ranges.
Kitchen scales work well. That's what I use. When they get bigger just put a shoebox top on it and tare it. I use grams because it's a good unit size for their weight but if your scale doesn't measure grams then you can use ounces and just keep track that way.
NOTE : every hatchling and juvenile beardie is different, and there are lots of aspects of husbandry and the conditions it lives under that can influence the growth rate of a beardie when young as well as it's parentage.
I just set Swordtail's timer for his bath and paused it so I could actually fill his soaking bowl up and he crawled over my phone and canceled the timer
Mirage came out of brumation on April 26. He was doing great. On May 2 he started acting funny. We just redid his tank, and he keeps going into one of his hides. He just lays there. He shows no intrest in food. HELP!