Home Arrow Spine Calculator
Arrow Spine Calculator
Calculate the correct arrow spine for your compound bow, recurve, or longbow based on draw weight, arrow length, and point weight. Includes spine charts for Easton, Gold Tip, Victory, and Carbon Express arrows. No sign-ups. Instant results.
Quick navigation: Calculator · Spine Charts · What is Spine? · Brand Calculators · FAQs
Shop arrows in your recommended spine
Once you have your spine number, these are the best places to find matched shafts:
- Optics Planet — recurve, traditional, and carbon shafts by spine
- Carbon arrows on Amazon — Easton, Gold Tip, Carbon Express, Victory
- All arrow types on Amazon — aluminum, carbon, and hybrid shafts
💡 Tip: Always test arrows before buying in bulk. Borrow or buy a few shafts to verify they fly well from your bow.
Example calculation
Let's find the correct spine for a typical recurve bow setup:
| Measurement | Value |
|---|---|
| Bow type | Recurve bow |
| Draw weight | 45 pounds |
| Arrow length | 29 inches |
| Point weight | 125 grains |
| Recommended spine | 500-600 spine (0.500"-0.600" deflection) |
For this setup, popular choices include Easton Carbon One 500, Gold Tip Traditional 500, or Victory VAP 500. Browse 500-spine recurve arrows at Optics Planet or Amazon carbon arrows. For compound hunters, see Centerpoint Archery for hunting shafts by spine.
🎯 Know your spine? Complete your arrow setup:
Reference: Arrow Spine Chart — full draw weight lookup tables
for recurve, compound, and traditional bows.
Next: Arrow Weight Calculator — total arrow weight in
grains.
Then: FOC Calculator — optimise front of center balance.
Then: Kinetic Energy Calculator — verify hunting
power.
Tune: How to Tie a D Loop — install and size your D loop
before paper tuning.
Shop: Archery Supplies — carbon arrows, aluminum shafts, and
components.
Understanding arrow spine
What is arrow spine?
Arrow spine measures how much an arrow shaft bends when force is applied. It's measured by supporting a 29-inch arrow shaft at both ends, hanging a 2-pound weight from the center, and measuring how much it deflects. The deflection in thousandths of an inch becomes the spine rating.
For example, a 500 spine arrow deflects 0.500 inches (half an inch). Lower numbers mean stiffer arrows (300 is stiffer than 500). Higher numbers mean weaker, more flexible arrows (600 is weaker than 500).
Why arrow spine matters
When you release an arrow, it doesn't fly straight immediately. The string pushes the nock forward, causing the shaft to flex and bend around the bow (called archer's paradox). The arrow literally bends around the riser as it leaves the bow.
If the spine is correct, the arrow flexes just enough to clear the bow cleanly and then straightens out in flight. If the spine is wrong, the arrow flexes too much or too little, causing it to fly erratically and hit off target.
Factors that affect required spine
- Draw weight: Higher draw weight = stiffer spine needed (lower spine number)
- Arrow length: Longer arrows behave dynamically weaker, which can require a stiffer (lower-numbered) shaft
- Point weight: Heavier front weight makes the shaft behave dynamically weaker, which can require a stiffer (lower-numbered) shaft
- Bow type: Compounds and recurves require different spines due to how they release energy
- Arrow material: Carbon, aluminum, and wood all have different stiffness characteristics
How to choose the right arrow spine
📏 Measure accurately
Arrow length is measured from the nock throat (where string sits) to the end of the shaft. Don't guess - measure your actual draw length or current arrows.
⚖️ Know your draw weight
Use the actual draw weight at YOUR draw length, not the bow's marked weight. Compound shooters should use peak weight, not holding weight.
🎯 Consider your point weight
Heavier points (broadheads) make arrows act weaker. If you'll hunt with 125-grain broadheads, factor that into your spine selection.
🔍 Test before buying
Buy a few sample arrows in the recommended spine range. Shoot them and see which groups best before ordering a full dozen.
Need a quick reference without the calculator? See the arrow spine chart for draw weight ranges at a glance. Shop carbon arrows on Amazon or browse all arrow types to find shafts in your recommended spine.
Common arrow spine ratings by bow type
Carbon-style spine numbers such as 300, 340, 400, 500, and 600 describe static shaft deflection: lower numbers are stiffer. The correct number cannot be chosen from draw weight alone.
Recurve
Use actual draw weight at your draw length plus finished shaft length and point/component weight.
Compound
Also account for bow speed and release method. Easton's hunting chart explicitly changes effective bow weight for faster compounds.
Longbow / traditional
Use the traditional column or the shaft maker's traditional selector; center-shot geometry and release style can shift tune.
Aluminum
Four-digit aluminum sizes are not interchangeable with a carbon-style spine label. Use the manufacturer's aluminum selection chart.
For a quick visual reference, see our Arrow Spine Chart. For the final purchase, verify the exact shaft model with its manufacturer's current selector.
Easton, Gold Tip & Victory spine selectors
This calculator is not a universal AMO spine formula. Its starting range is based on Easton's published Hunting Arrow Size Selection chart (301055-A), including Easton's point-weight and compound-speed adjustments. Other manufacturers use their own model-specific grouping and component assumptions.
Use the result here to narrow the range, then confirm the exact shaft with the manufacturer you plan to buy.
Gold Tip
Open Gold Tip's spine selector, which includes total front-component weight guidance.
Victory
Open Victory's arrow guide, which includes bow speed and component inputs.
Once the model-specific result is confirmed, shop shafts in that spine range.
Arrow spine quick reference guide
Understanding spine numbers
| Spine Number | Stiffness | Common Use |
|---|---|---|
| 200-300 | Very stiff | Heavy compound bows (70+ lbs) |
| 300-400 | Stiff | Compounds 55-70 lbs, hunting |
| 400-500 | Medium | Compounds 45-60 lbs, recurves 40-50 lbs |
| 500-600 | Medium-soft | Recurves 35-45 lbs, lighter compounds |
| 600-800 | Soft | Recurves 25-35 lbs, youth bows |
| 800-1000 | Very soft | Youth bows, very light draw weights |
Popular arrow brands by spine
Carbon arrows (common brands):
- Easton: Carbon One, FMJ, Axis, Bloodline (300, 340, 400, 500, 600 spines)
- Gold Tip: Hunter, Warrior, Velocity, Traditional (300, 340, 400, 500, 600 spines)
- Carbon Express: Maxima, PileDriver, Predator (250, 350, 450, 550 spines)
- Victory: RIP, VAP, V-Force (300, 350, 400, 500, 600 spines)
Aluminum arrows (target shooting):
- Easton X10, X23, ACE: Use 4-digit codes (e.g., 1816, 2013, 2213)
- First 2 digits = diameter in 64ths of inch
- Last 2 digits = wall thickness in thousandths
💡 Always check manufacturer spine charts for your specific arrow model. Spine ratings can vary slightly between brands.
Note: the table above groups draw weights broadly for quick reference. For precise spine by exact draw weight and arrow length, use the detailed recurve and compound tables above, or the calculator at the top of this page.
Arrow spine calculator FAQs
What is arrow spine and why does it matter?
Arrow spine describes shaft stiffness. The shaft flexes when energy is transferred from the bow, and the correct static spine range helps the finished arrow tune and recover consistently for the specific bow setup.
What chart does this calculator use?
The starting ranges are based on Easton's Hunting Arrow Size Selection chart 301055-A. The calculator applies Easton's point-weight adjustment and, for compound bows, the selected speed-rating and release-type adjustment. Final shaft choice should still be checked with the manufacturer of the arrow you intend to buy.
Why can Gold Tip or Victory give me a different result?
Manufacturer selectors use their own shaft families and component assumptions. Gold Tip explicitly includes total front-component weight, while Victory includes bow speed and component inputs. A difference does not mean one tool is universally correct for every shaft; use the selector for the exact model you plan to shoot.
How do I measure arrow length for this calculator?
For the Easton hunting chart used here, measure cut shaft length from the throat of the nock to the end of the shaft, excluding the point and insert. Other manufacturers may define their selector input differently, so follow the wording on the final brand-specific tool.
What is the difference between static and dynamic spine?
Static spine is the shaft's measured deflection under a standardized test. Dynamic spine describes how that finished arrow behaves when shot from a specific bow. Shaft length, front weight, bow speed, release style, and tuning can change dynamic behavior without changing the static spine label printed on the shaft.
Does a heavier point mean I need a weaker spine number?
No. Adding front weight makes the arrow behave dynamically weaker, which can require a stiffer shaft — a lower carbon-style spine number. Easton's hunting chart handles this by adding effective bow weight when the point is heavier than its 100-grain reference.
Can cutting an arrow change its labeled spine?
Cutting a shaft shorter makes it behave dynamically stiffer, but the labeled static spine does not change. A 400-spine shaft remains a 400-spine shaft after cutting. Tune in small increments and stay within the manufacturer's safe length guidance.