The old grams per/watt/month
If your good you can get around 0.5 grams per watt month
1000 grams /1000 watts / 2 months bloom = 0.5 g/w/m
Note time is part of the math.
The best I have seen and believe was TIC on overgrow got 0.6 with a scrog system.
Note that is dried,cured, clean
Must admit my average is 0.468 gwm
When you have dreams of trimming pot, to lazy to pick a popcorn bud, then you have down, to doing it right.
Having fun does help, REMEMBER NEVER TELL ANYBODY YOU GROW, OR ANYTHING ELSE.