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? · FAQs
💡 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 spine-matched arrows at retailers like 3Rivers Archery or Lancaster Archery.
🎯 Know your spine? Complete your arrow setup:
- Next: Use Arrow Weight Calculator to calculate total arrow weight
- Then: Use FOC Calculator to optimize arrow balance
- Finally: Check Kinetic Energy for hunting power
🛒 Shop: Archery Supplies for 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 = weaker effective spine (higher spine number needed)
- Point weight: Heavier points = weaker effective spine (can use slightly higher spine number)
- 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.
🛒 Shop carbon arrows on Amazon or browse all arrow types to find shafts in your recommended spine.
Common arrow spine ratings by bow type
Recurve bows (barebow & Olympic)
| Draw Weight | Arrow Length 28" | Arrow Length 30" |
|---|---|---|
| 25-30 lbs | 800-900 spine | 900-1000 spine |
| 30-35 lbs | 700-800 spine | 800-900 spine |
| 35-40 lbs | 600-700 spine | 700-800 spine |
| 40-45 lbs | 500-600 spine | 600-700 spine |
| 45-50 lbs | 400-500 spine | 500-600 spine |
| 50-55 lbs | 340-400 spine | 400-500 spine |
Compound bows
Compound bows typically need stiffer arrows than recurves at the same draw weight due to the mechanical advantage and faster energy release. Most modern compounds (60-70 lb draw weight, 28-30" arrows) use spines between 300-400.
Check your actual draw weight and consult manufacturer spine charts for your specific arrow brand, as carbon and aluminum spines differ.
Traditional longbows and wood arrows
Longbows and self bows generally require slightly weaker spines than recurves at the same draw weight because they're usually shot off the shelf or hand, creating more arrow paradox. Add 50-100 spine deflection (one spine group weaker) compared to recurve recommendations.
Wood arrow spine is measured differently than carbon — it uses a pounds-of-deflection scale rather than thousandths of an inch. A wood shaft spined at "45-50#" is designed for a bow drawing 45-50 pounds. Match the wood spine rating directly to your draw weight for traditional setups. See arrow spine chart for quick reference.
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.
Arrow spine calculator FAQs
What is arrow spine and why does it matter?
Arrow spine is the measurement of an arrow shaft's stiffness. When you release an arrow, it flexes around the bow. If the spine is too weak, the arrow will flex too much and fly erratically. If it's too stiff, it won't flex enough and will also fly poorly. The correct spine ensures the arrow flexes just right for straight, accurate flight.
Where can I find an arrow spine chart?
Arrow spine charts are available from arrow manufacturers (Easton, Gold Tip, Carbon Express, Victory) and show recommended spine for different draw weights and arrow lengths. Our spine charts above provide general guidelines for recurve, compound, and longbow setups. For brand-specific recommendations, check the manufacturer's website or consult their printed spine selector charts available at archery shops.
How do I measure my arrow length?
Measure from the nock's throat (where the string sits) to the end of the shaft, not including the point. For safety, add 1-2 inches to your draw length. A properly sized arrow should extend 1-2 inches past your arrow rest at full draw. Use our arrow length calculator for precise measurements.
What's the difference between static and dynamic spine?
Static spine is measured by hanging a weight from the center of a 29-inch arrow shaft and measuring deflection. Dynamic spine is how the arrow actually flexes when shot from your specific bow setup. This calculator helps you find the right static spine that will give you proper dynamic spine with your bow.
Can I use the same spine chart for recurve and compound bows?
No. Recurve and compound bows require different spine calculations because they store and release energy differently. Compound bows have let-off and cams, which affect how the arrow leaves the bow. Always use spine recommendations specific to your bow type.
What happens if my arrow spine is wrong?
Incorrect spine causes erratic arrow flight, poor accuracy, and inconsistent grouping. Arrows that are too weak will flex excessively and often impact left (for right-handed shooters). Arrows that are too stiff won't flex enough and typically impact right. Proper spine is essential for consistent, accurate shooting.
Do carbon and aluminum arrows use the same spine ratings?
No. Carbon arrows typically use a 3-digit number (300, 400, 500) while aluminum arrows often use a 4-digit code (1816, 2014, 2213) where the first two digits are diameter in 64ths of an inch and the last two are wall thickness. Always check manufacturer-specific spine charts for the arrow material you're using.
Should I use a different spine for hunting vs. target shooting?
Yes, potentially. Hunting arrows typically use heavier broadheads (100-125 grains vs. 75-100 grain field points), which makes arrows act weaker. You may need to go one spine group stiffer when switching from field points to broadheads. Calculate your setup with your intended point weight for the most accurate recommendation.
Can I make arrows stiffer or weaker after I buy them?
Cutting arrows shorter makes them effectively stiffer (stronger spine). Adding weight to the front (heavier points) makes them weaker. However, there are limits to these adjustments. It's better to start with the correct spine than try to compensate afterward. Use our FOC calculator to optimize your arrow balance.