I drew a really good elk tag this year and am now in the obsessing over my equipment stage. Building some new arrows and was wondering (don't know why, never worried about it before) what my FOC is. Started thinking on how to cipher it and thought I would check the how to section. Lo and behold Mr. Rob has a handy dandy excel file there to figger foc for you. Been here a few years now and still amazes me on the info available to us here. Thank you Rob, Terry and all you guys that contribute so much of your knowledge. I very much appreciate it.    

I messed with FOC arrows from info I read here, too. Good stuff to learn no matter what you're into.

I'm sticking with my set-ups I started with, turns out I was pretty close in the first place by keeping it simple. Dang near 20 years at this, full circle I guess...

The absolute best place to be online for sure! For normal folks like us of course.  

Tuning trumps FOC all day long, if what you're using now shoots well and you have lots of confidence in them, stick with them.  If ain't broke, don't fix it!  Congrats on the elk tag!

I used to measure FOC but never worry about it anymore.Usally with at least a 125 gr. point or head you have enough on a well tuned arrow.I agree with slivrslingr tuning trumps FOC.I prefer a tuned arrow that flys straight and fits my bow.

Yup, not changing a thing. Turns out the arrow I have been using the last few years comes in at 580gr with 23% foc, fly great and I know they work. Just thought that little calculater of Robs was pretty neat.