Board Feet Calculator
Say you got a log of a certain diameter - how many board feet of lumber will you get from it?
https://www.woodweb.com/cgi-bin/calculators/calc.pl?calculator=log_volume
12" by 12' - gets you 70 bf. But imagine you got a huge fallen tree of 3' diameter, where you have one nice 8' long section. 480 board feet!