Spine Calculator

Find the perfect arrow to maximize your shooting! Match the dynamic spine of bow and arrow for optimal performance.

PLEASE NOTE: This is a mathematical formula for selecting a bow/arrow combination. In theory, the results from the data you enter should work perfectly, BUT in real world use, variations will happen. This can be from your personal shooting form (creeping, plucking the string, etc), or incorrect data entered (bow having a different center cut than what is listed, bow weight different than what is printed on bow, etc).

3Rivers does not guarantee results provided by this tool. We ALWAYS recommend getting a shafting test kit to confirm a set up prior to buying a set spine. See ALL Test Kits HERE. Feel free to call our Tech line Monday-Friday 9-5 EST at 1-260-587-9501.