Recurve Arrow Spine Calculator

Guide

Why Recurve Spine Selection Isn't Compound Spine Selection

💡 Quick Summary

Core Insight: Recurve bow weight is marked at a fixed 28″ AMO draw length, not your own draw — so the first step is correcting it to your actual draw (roughly 2 lbs per inch of difference), then adjusting for limb type, arrow length and point weight to get one effective bow weight you can run through any current manufacturer chart.

Ideal For: Recurve or traditional-longbow shooters sizing a first set of shafts, or sanity-checking a number a shop already gave them.

How Is the Effective Bow Weight Built?

Four adjustments stack on top of the marked bow weight, each one lifted from a documented recurve/traditional selection convention rather than a compound-bow formula:

Draw length correction — recurve and longbow weight is printed at the AMO-standard 28″ draw. This tool adds roughly 2 lbs for every inch your draw runs longer than 28″, and subtracts the same for a shorter draw — a conservative, widely cited rate; some limbs run closer to 2.5–3 lbs per inch, so a bow scale reading at your real draw is the way to confirm it exactly.

Limb type — Easton's own published recurve/traditional chart applies no adjustment for modern carbon or foam-core limbs, and roughly −5 lbs of effective weight for wood or fiberglass beginner-style limbs, which cast measurably slower at the same marked poundage.

Point weight — heavier points make the front of the arrow effectively weaker in flight, so this tool adds effective weight above a 125 gr reference point (and subtracts below it) at roughly 3 lbs per 25 gr, extending the same adjustment magnitude Easton publishes for its compound chart to the recurve case.

Arrow length — every inch a shaft is cut longer than a 28″ reference adds roughly 5 lbs of effective weight (a longer shaft flexes more for the same stiffness); every inch shorter subtracts the same, matching the general convention used across manufacturer length columns.

⚠️ Important Limitations

This effective-weight build-up is ArcheryEra's own transparent model, not a single manufacturer's exact published number for every input combination — it is meant to get you close, fast, using documented adjustment directions and typical magnitudes. The spine family table below is recalibrated directly against Easton's own recurve/finger-release hunting chart at a 28″ arrow length, not a generic or compound-bow table — recurve and compound spine numbers diverge sharply at lower poundage, so the two Quick Tools intentionally use separate tables. Always confirm the final shaft and spine against your shaft manufacturer's current selection chart, and re-verify with a paper tune once arrows are built.

Sources & Methodology

The underlying static-spine test — the basis for every numbered shaft spine — is described in Easton's own Making Sense of Arrow Spine and in the ASTM F2031 breakdown at targetcrazy.com's ATA/ASTM spine standards page: a shaft supported at two points roughly 28″ apart, loaded with a 1.94 lb (880 g) center weight, with the deflection in thousandths of an inch giving the spine number. The point-weight and limb-type adjustment magnitudes above come directly from Easton's own Arrow Shaft Selection chart, which documents both the compound point-weight rule this tool extends to recurve and the recurve-specific carbon-vs-wood/glass limb adjustment. The spine family table itself is rebuilt directly off Easton's own recurve bow (finger-release) arrow spine chart, read at its 28″ arrow-length column across every listed draw-weight row — not a compound-bow table repurposed for recurve. The existence of dedicated recurve/longbow selection charts, separate from compound charts, is confirmed in 3Rivers Archery's published spine selection charts. For the final brand-specific shaft and size, run this effective weight through Easton's own Target & Hunting Arrow Selector alongside your arrow length and point weight.

Frequently Asked Questions