Target arrow build: 15.05% FOC
A 100 grain point on a 6.5 GPI, 29 inch shaft gives 15.05% FOC (extreme foc) and a total arrow weight of 317.5 grains. Adjust any component to see the effect.
A 100 grain point on a 29 inch shaft at 6.5 GPI balances 18.87 inches from the nock throat, giving 15.05% front of center — extreme foc — at a total arrow weight of 317.5 grains. Light shaft, small vanes and a field point — a flat-shooting target setup with normal FOC.
Arrow build
Component weights in grains; shaft weight comes from GPI × length.
For grains per pound
Extreme FOC — Ashby-style setup. Strong penetration and stability; expect a noticeably more arcing trajectory past 30 yards.
How this was calculated
Arrow weight
- Shaft: 188.5 gr
- Front end (point + insert + collar): 112.0 gr
- Back end (nock + fletching + wrap): 17.0 gr
- Total: 317.5 grains
- 5.29 grains per pound of draw weight
The balance point is estimated by treating the shaft as a uniform rod. Weigh and balance the finished arrow for an exact figure.
What the number means
| FOC range | Description |
|---|---|
| under 7% | Low FOC — Flatter trajectory but less forgiving in flight. Common on target setups shooting light points. |
| 7–10% | Normal FOC — The range most factory arrows land in. A good all-round balance of trajectory and stability. |
| 10–15% | High FOC — Popular for hunting: better arrow flight stability and forgiveness, with only a modest drop in trajectory. |
| 15–19% | Extreme FOC — Ashby-style setup. Strong penetration and stability; expect a noticeably more arcing trajectory past 30 yards. |
| 19%+ | Ultra-extreme FOC — Maximum penetration territory. Trajectory drops off quickly, and arrow tuning gets fussy. |
This build in numbers
| Shaft length | 29 in |
| Shaft GPI | 6.5 grains per inch |
| Shaft weight | 188.5 gr |
| Point | 100 gr |
| Insert | 12 gr |
| Nock | 8 gr |
| Fletching | 9 gr |
| Total arrow weight | 317.5 gr |
| Balance point | 18.87 in from the nock throat |
| Front of center | 15.05% (Extreme FOC) |
| Grains per pound | 5.77 gpp at 55 lb |
Ashby-style setup. Strong penetration and stability; expect a noticeably more arcing trajectory past 30 yards.
Compare other builds
Frequently asked questions
What FOC does a 100 grain point give? ▾
On this build — a 29 inch shaft at 6.5 GPI with a 12 grain insert, 8 grain nock and 9 grains of fletching — a 100 grain point gives 15.05% FOC, which counts as extreme foc. Change any component in the calculator to see how the number moves.
How much does this arrow weigh? ▾
About 317.5 grains in total: 188.5 grains of shaft, 112 grains up front, and 17 grains at the back. At 55 lb of draw weight that is 5.77 grains per pound.
Is 15.05% a good FOC? ▾
Extreme FOC. Ashby-style setup. Strong penetration and stability; expect a noticeably more arcing trajectory past 30 yards.
Will this estimate match my measured FOC? ▾
It should be close. The estimate treats the shaft as a uniform rod and puts the front components right at the tip, so a build with a long outsert or an unusual shaft taper can differ by a few tenths of a percent. Balance the finished arrow for the exact figure.
About this Calculator
A 100 grain point on a 6.5 GPI, 29 inch shaft gives 15.05% FOC (extreme foc) and a total arrow weight of 317.5 grains. Adjust any component to see the effect.