Calculate arrow front of center (FOC) using the same ATA/AMO formula that Podium Archery, Gold Tip, Easton, and Ranch Fairy tools use. Compare component builds side by side and see which tuning decisions move FOC the most.
Enter your full build. FOC calculates using ATA/AMO formula, and a break-even analysis shows where FOC lands for the given component stack.
FOC% = ((A − L/2) ÷ L) × 100
A = distance from nock throat to balance point; L = total shaft length.
Every legitimate FOC calculator uses the same formula. The differences come from the input measurements, not the math.
| Brand Tool | Formula | Extra Features | Notes |
|---|---|---|---|
| Podium Archer FOC Calculator | ATA/AMO | Component stack presets, heavy-arrow focus | Same result as ours when inputs match |
| Gold Tip FOC Calculator | ATA/AMO | Gold Tip shaft presets | See our Gold Tip version |
| Easton FOC Calculator | ATA/AMO | Easton FMJ / Axis presets | See our Easton version |
| Ranch Fairy FOC Calculator | ATA/AMO | Heavy arrow focus, podcast-driven | See our EFOC version |
| Ashby FOC Calculator | ATA/AMO | Penetration tiers (EFOC) | See our EFOC breakdown |
Podium Archery-style builds typically target 15–22% FOC for hunting. These component stacks hit common targets.
| Target FOC | Shaft GPI | Insert | Point | Typical Total |
|---|---|---|---|---|
| 10–12% | 8–9 gpi | 20 gr aluminum | 100–125 gr | 390–430 gr |
| 13–15% | 9–10 gpi | 50 gr brass | 125 gr | 440–490 gr |
| 16–18% | 10–11 gpi | 75 gr brass | 150 gr | 500–560 gr |
| 19–22% (EFOC) | 10–12 gpi | 100 gr brass or steel | 150–200 gr | 550–650 gr |
| 22%+ (Ultra) | 11–13 gpi | 125–150 gr steel | 200–300 gr | 650–800 gr |
Yes in formula. Every legitimate FOC calculator uses FOC% = ((A − L/2) ÷ L) × 100. Differences come only from what each tool pre-loads or how it rounds inputs.
Podium Archery promotes the heavy-arrow, high-FOC philosophy for improved penetration and broadhead control on large game. Their tuning guidance pairs EFOC builds with matched spine and cut-on-contact broadheads.
Use both and compare. Our arrow spine calculator gives a quick estimate; Podium's guide gives a brand-specific second opinion. If they disagree, validate with a bare-shaft test.
Most Podium-style heavy builds target 15–20% FOC for deer. That range balances penetration, trajectory, and spine demands. Going above 22% is typically reserved for elk or dangerous game.
Yes. Ranch Fairy uses the same formula. Use our high FOC / EFOC calculator for a Ranch Fairy-style comparison with Ashby tier classification.
No. Podium publishes detailed tuning guides alongside their calculator. Use this page for quick FOC math, then cross-reference their guides for build and broadhead recommendations.