Arrow Weight Calculator

Pick a shaft model from the dropdown (each carries a GPI rating), enter your cut length, point weight, insert (aluminum or brass), nock weight, vane count × vane weight, glue estimate, and your bow's draw weight. The calculator sums every component into a real-time breakdown, returns total grains, and checks the IBO 5-grains-per-pound safety floor automatically. Unlike the homepage calculator which takes a single arrow-weight number, this tool breaks the build into its components so you can see exactly where the grains are and tune them.

GPI (grains per inch) is the manufacturer-published weight of one inch of bare arrow shaft. To calculate arrow weight from GPI: bare shaft weight = GPI × cut length. A 400-spine Easton Axis at 8.1 GPI cut to 28 inches weighs 8.1 × 28 = 226.8 grains bare. Add point + insert + nock + vanes + glue to get total arrow weight. GPI is the single biggest driver of bare-shaft weight, so shaft model selection matters more than any other single decision for total grain count.

The IBO speed specification is measured with a 350-grain arrow at 70 lb draw weight, 30″ draw length, and no string accessories — that 350-grain reference is exactly 5 grains per pound (5 × 70 = 350). The 5 gr/lb rule is the minimum safe arrow weight for any bow: total arrow grains ÷ peak draw weight must be ≥ 5, or the bow risks dry-fire-like limb damage from too little arrow mass to absorb the stored energy. This calculator flags red if your build drops below 5 gr/lb for your draw weight.

Sum every component: total = (GPI × cut length) + point + insert + nock + (vane count × vane weight) + glue. For a 28″ Easton Axis 400 (8.1 GPI = 226.8) + 100gr point + 20gr aluminum insert + 12gr nock + 15gr vanes (3×5) + 7gr glue = 380.8 grains. Weigh the finished arrow on a grain scale to verify — spec-sheet GPI has ±0.5 gr/in tolerance, so a calculated 380gr arrow typically weighs 378–384gr actual.

An arrow grain calculator (this tool) sums component weights to return total grains — a mass tool. A speed calculator (the homepage tool) takes that grain count as an input and returns fps — a velocity tool. The two work in sequence: build the arrow here to get total grains, then feed that grain count into the homepage speed calculator to predict fps. The arrow builder calculator here is the component-level front end to the speed calculation.

A brass insert adds 35–75 grains versus an aluminum insert of the same fit — an aluminum insert weighs 15–25gr, a brass insert weighs 50–100gr. That gain is concentrated at the front of the arrow, so it also shifts FOC up by 3–5%. If you swap aluminum→brass on a 380gr build, total weight jumps to ~420–440gr and FOC rises noticeably — re-verify speed and spine after the swap.

Typically within 2–4 grains. Spec-sheet GPI has a tolerance of roughly ±0.5 gr/in (so a 28″ shaft can be ±14gr off the published number), and glue weight is an estimate. For tournament or ethical-hunting builds, weigh every finished arrow on a grain scale and sort into ±2-grain matched groups — calculated weight is a planning number, weighed weight is the truth.

Target and 3D: 5–6.5 gr/lb (350–455gr at 70 lb) for flat trajectory and forgiving flight. General whitetail deer: 6.5–8 gr/lb (455–560gr) — enough momentum for clean pass-through. Elk and bone-breaking: 8–10 gr/lb (560–700gr) for maximum momentum through shoulder. Dangerous game: 10+ gr/lb. Heavier builds carry more momentum but lose speed; the trade-off is why the homepage speed calculator and this weight calculator are used together.

Indirectly — total grain weight itself does not change static spine, but the component choices that add weight (heavier point, brass insert) weaken dynamic spine because they concentrate mass forward. Adding 50gr of point weight can weaken dynamic spine by a full grade. This is why re-tuning spine after a weight change matters: build the weight here, then re-verify spine with the Arrow Spine Calculator.

Yes — two charts. The Brand GPI Reference Table above is the 'arrow grain chart': it lists the grains-per-inch of every popular shaft (Easton FMJ 5mm 300 = 11.3 GPI, Easton Axis 5mm 400 = 8.1, Gold Tip Hunter 400 = 8.9, Victory VAP 400 = 7.5, etc.), so you can read bare-shaft grain density at a glance and multiply by your cut length. The Arrow Weight by Game Class block is the 'arrow weight chart': it maps total finished-arrow weight bands (target 5–6.5 gr/lb, whitetail 6.5–8 gr/lb, elk 8–10 gr/lb) to the game you hunt, with example builds. Together they answer both 'how many grains per inch is this shaft' and 'how heavy should my finished arrow be' — the two senses of 'arrow weight chart' that searchers mean.

The weight of a finished hunting arrow runs roughly 350 to 600 grains; target arrows sit lighter at 250–400 grains, and heavy elk/bone-breaking builds push 600–800+. The bare shaft is only part of it — a 28″ Easton Axis 400 at 8.1 GPI is 226.8 grains bare, then a 100gr point, 20gr aluminum insert, 12gr nock, 15gr of vanes and ~7gr of glue bring the finished weight to ~381 grains. Use the builder above to sum your exact components, or read the Brand GPI Reference Table for the per-inch weight of any popular shaft. The one floor every arrow weight must clear is the IBO 5 grains-per-pound minimum (5 × your draw weight) — below it the bow risks dry-fire-like limb damage.