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. The same correction decides whether a short-draw archer clears a state’s hunting minimum; I worked it through for New Jersey and Pennsylvania on the minimum draw weight by state page.

Limb type — Easton's 2023 target 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 3 lbs of effective weight for every 25 gr above a 100 gr point and takes off the same below it. That’s the rule printed on both of Easton’s 2023 recurve charts, which are built on 100 gr points. A 125 gr point adds 3 lbs.

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. Pick the length from a full-draw clearance check before you trim for spine.

Shooting style — the effective weight comes out the same for every style, but the table it’s read against doesn’t. Olympic / Target reads Easton’s 2023 target chart; Barebow and Traditional read the 2023 hunting chart. Barebow goes on the hunting chart because a barebow rig is shot like a traditional recurve, off a shelf or plunger with no sight, clicker or stabilizers, and the 2023 hunting chart is the one with Easton’s traditional recurve column; the target chart is the one this tool pairs with Olympic-style setups. The target chart runs weaker for the same bow, so for Barebow the hunting chart is the stiff-side start the on-screen note describes, and a bareshaft tune has the last word. At this tool’s default inputs the effective weight is 41 lbs, which lands on 570–640 with Olympic / Target and on 400–500 with Barebow (modeled).

⚠️ 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 table below is read off Easton's 2023 recurve charts at a 28″ arrow length (the target chart for Olympic / Target, the hunting chart for the other two styles), 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. The hunting chart prints no row under 24 lbs and the target chart none above 73 lbs; past those edges the tool shows the nearest row and an out-of-range warning. 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 the one Easton describes for its numbered shafts and the one written into the ATA/ASTM F2031 spine standard: 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. Both of Easton's 2023 selection charts state the point-weight rule for recurves directly: 100 gr points are the baseline, and every 25 gr above or below moves the bow weight 3 lbs. The −5 lb wood/glass limb rule comes from the 2023 target chart's recurve finger-release section, and this tool applies it to both tables. The Barebow and Traditional table is read off the 2023 hunting chart's traditional recurve rows at the 28″ arrow-length column; the Olympic / Target table is read off the target chart's 28″ column, 12 rows from 20 lbs and under to 68–73 lbs. Neither is a compound-bow table repurposed for recurve. Shaft makers publish recurve and longbow selection charts separate from their compound charts. For the final brand-specific shaft and size, Easton’s online selector can match this effective weight to a specific shaft once you add your arrow length and point weight.

Recalibrated against Easton’s 2023 charts on October 19, 2026. The spine bands and the point-weight reference (now 100 gr, as on Easton’s charts) follow Easton’s 2023 hunting chart; the Olympic / Target style reads Easton’s 2023 target chart, which runs weaker for the same bow. Before that date the tool measured point weight from 125 gr and used one table for every style, so a setup saved earlier can show a different result today.

Frequently Asked Questions