What arrow spine do I need?
An arrow that's too limp or too stiff for your setup won't fly straight, no matter how well you shoot. Spine (a shaft's stiffness) depends on your draw weight, arrow length and point weight together. Enter yours for a sensible starting spine - then bare-shaft tune to lock it in.
A mid-range hunting setup - 340 spine is the most common deer-hunting shaft.
Remember: lower spine number = stiffer arrow. A longer arrow or a heavier point both make a shaft act weaker, so both push you toward a stiffer (lower-number) spine. When you're on the line between two, the stiffer one is the safer, more forgiving choice.
⚠️ A starting point only. Every arrow maker publishes its own spine chart and they don't fully agree, and cam aggressiveness, rest type, nock fit and your release all shift dynamic spine. Use this to get in the right ballpark, then confirm by bare-shaft or paper tuning with your actual bow before you trust a broadhead to it. When in doubt, ask a pro shop to spine-match your build.