Arrow Build Calculator

Point weight and insert weight both sit at the very front tip of the arrow in this calculation, so a grain added to either one has identical leverage on shifting the balance point forward -- point weight isn't inherently more powerful, gram for gram. What makes point weight feel more influential in practice is that it has a much wider practical range (roughly 50 to 300+ grains for field points and broadheads) than insert weight typically does, so changing points usually moves more total grains than changing inserts. Vanes, nock, and wrap sit at the rear in this model, so equal weight added there moves the balance point in the opposite direction and with less overall effect since they're lighter components to begin with.

The calculator treats the shaft's own weight as evenly distributed along its length, centered at the shaft's midpoint, so adding more shaft mass pulls the overall balance point back toward the geometric center of the arrow rather than forward. Since FOC measures how far forward of center the balance point sits, more shaft weight (whether from a heavier-per-inch shaft or a longer cut length) works against the point weight's forward pull and reduces the resulting FOC percentage.

Target archery setups typically aim for 10-15% FOC, which balances stability with flat trajectory and forgiveness on slightly imperfect releases. Hunting arrows, especially with heavier broadhead points, commonly run 15-19% FOC or even higher, since a more front-heavy arrow penetrates more consistently and recovers from paradox flex faster after leaving the bow, at some cost to trajectory flatness compared to a lower-FOC target arrow.

Total arrow weight is the sum of every component in grains for one specific, fully-built arrow, while grains per inch divides that total by shaft length so you can compare arrows of different lengths on equal terms. Two arrows can have very different total weights simply because one is cut longer than the other, so GPI is the number archers and manufacturers typically use when comparing shaft specifications across different draw lengths.