Arrow Spine Calculator
Calculate the recommended arrow spine (stiffness) based on bow draw weight, arrow length, and point weight. This tool helps archers select the correct arrow spine for optimal performance.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to Use the Arrow Spine Calculator
This calculator estimates the approximate spine (stiffness) needed for your arrows based on three inputs. A higher spine number means a weaker arrow.
- Enter Draw Weight (in pounds, 10–100): Your bow’s draw weight at your draw length.
- Enter Arrow Length (in inches, 20–36): The full length of your arrow shaft.
- Enter Point Weight (in grains, 50–300): The weight of your arrow tip or broadhead.
- Click Calculate Spine to see the result.
Formula: Spine = (Draw Weight × Arrow Length) ÷ Point Weight. The result is an approximate value; always test arrows before use.
All values must be in imperial units (lbs, inches, grains).
Previous Results
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Frequently Asked Questions
Arrow spine refers to the stiffness of an arrow shaft. A stiffer arrow has a lower spine number, while a weaker arrow has a higher spine number. Choosing the correct spine is crucial for accuracy and safety.
This calculator uses a simplified formula: Spine = (Draw Weight × Arrow Length) / Point Weight. The result is an approximate spine value; always consult manufacturer charts for final selection.
The calculator validates inputs: draw weight 10-100 lbs, arrow length 20-36 inches, point weight 50-300 grains. Adjust your inputs to fit these ranges for a meaningful result.
