Spine Calculator

Select your bow brand and model for predetermined values on your bow. NOT a guaranteed match, use generic listings if your bow is not listed

The weight, in pounds, that your bow pulls at factory draw length. Normally written on the lower part of the riser, or bottom limb. Example: 50# @ 28" is factory weight of 50#. Enter this information in whole numbers: 50

The listed length a bow is to be drawn. The industry standard is 28 inches. Example: 50# @ 28" is factory draw length of 28". Enter this information in whole numbers: 28

The length you pull your bow back to anchor. Varies from shooter to shooter, and can vary from factory draw length. Can determine by drawing back an arrow and having someone mark the arrow on the outside of the bow when at anchor. Measure arrow from valley of nock to the mark.

How deep cut in the arrow shelf is on the riser. Measure (in inches) the width of the riser at its thickest point (right below arrow shelf cut-in). Then, measure (in inches) the depth of the arrow shelf not including strike plate (arrow rest), that comes later. Divide the overall width by two, then subtract shelf measurement. If a negative number your bow is cut past center. Choose from dropdown selection. If inbetween size, go deeper cut and add on to strike plate thickness the difference.

The part of the arrow rest that mounts to the side of the bow. Protects bow from arrow impacts during the shot.

Measured in inches. Example: 1/8" should be listed as 0.125

Refers to the type of bow string you shoot. If you are not sure about material (B50 or FastFlight), check with manufacturer. Strand count refers to how many strands of material make up the bow string.