What is it? What does mine need to be in my arrow?Why?I used a link to a FOC calculator and it said mine was 10.7% if i remember correctly. Is this good or bad?

It means front/forward of center. It'sa description of the percentage of the arrow's total weight that is located in the front half of the arrow.

I have found that broadhead tipped arrows withFOC's above 12% perform better for me. I even have a set of Easton FMJ's that have a FOC over 20% and they are awesome.
Raising your FOC to 12% to 15% can improve flight, groups, and penetration. FOC is just one of many variables to consider when building the ultimate hunting arrow.

Dan

Agree completely. I switched to 100 grain heads this season and just have not been satisfied with them. With a wrap and lighted nock, my FOC is just not as high as I want it so will be going back to 125's as soon as deer season is done (and before our pig hunt in late Jan).

Easton recommends 10-15% and imo,this is mainly due to spine.Below 10%,you can have serious flight issues,especially with broadheads.

If you choose the HIGH foc route,you need to make sure you are shooting a stiff arrow to accomodate the extra weight up front.

"THEY" say 10 percent for hunting is minimum. I prefer heavy, mine is 13.5. I have always settled in that area. I get consistant flight and groups and good down range trajectory. 10 will probably be fine but I prefer a little heavier.

So I'll ask the noobie question...how do you determine your FOC?

Forward of Center is a measure of how far the balance point of the arrow is in front of the center point of the arrow. The more weight you put up front the farther that fulcrum point moves toward the tip and the higher your FOC becomes. It's especially important in controlling arrow flight with broadheads. A low FOC gives the broadhead more control over the flight of the arrow as opposed to the fletching having more control on a higher FOC shaft. I've had decent flight out of shafts down as far as 11% FOC but prefer my current shafts at 15%. Another benefit is that a high FOC shaft has the fulcrum point farther forward around which it flexes on impact thereby decreasing the amplitude of deflection and allowing the shaft to spend that energy on penetration rather than deflection.

3/30 =.1 X 100= 10%

I actually don't measure to the front of the head,I just use the shaft as this is what Easton recommends.I would assume this has something to do with how they figure dynamic spine.