150 grain point build: 17.61% FOC
A 150 grain point on a 9.0 GPI, 28 inch shaft gives 17.61% FOC (extreme foc) and a total arrow weight of 483 grains. Adjust any component to see the effect.
A 150 grain point on a 28 inch shaft at 9.0 GPI balances 18.93 inches from the nock throat, giving 17.61% front of center — extreme foc — at a total arrow weight of 483 grains. A brass insert plus a heavy head pushes this build into high FOC territory.
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: 252.0 gr
- Front end (point + insert + collar): 200.0 gr
- Back end (nock + fletching + wrap): 31.0 gr
- Total: 483.0 grains
- 8.05 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 | 28 in |
| Shaft GPI | 9.0 grains per inch |
| Shaft weight | 252 gr |
| Point | 150 gr |
| Insert | 50 gr |
| Nock | 10 gr |
| Fletching | 21 gr |
| Total arrow weight | 483 gr |
| Balance point | 18.93 in from the nock throat |
| Front of center | 17.61% (Extreme FOC) |
| Grains per pound | 7.43 gpp at 65 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 150 grain point give? ▾
On this build — a 28 inch shaft at 9.0 GPI with a 50 grain insert, 10 grain nock and 21 grains of fletching — a 150 grain point gives 17.61% 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 483 grains in total: 252 grains of shaft, 200 grains up front, and 31 grains at the back. At 65 lb of draw weight that is 7.43 grains per pound.
Is 17.61% 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 150 grain point on a 9.0 GPI, 28 inch shaft gives 17.61% FOC (extreme foc) and a total arrow weight of 483 grains. Adjust any component to see the effect.