Compound bow arrow setup is a system: spine has to match the dynamic load of your bow, point weight drives both spine and FOC, total weight trades trajectory against penetration. The lab models the system end-to-end so you can move one variable and see the rest update in real time.
Inputs: peak draw weight, draw length, IBO speed, finished arrow length, shaft GPI, point weight, insert weight, nock weight, fletching weight, and target use case (target, 3D, hunting). Outputs: estimated fps, FOC%, kinetic energy in ft-lb, momentum in slug-fps, penetration index, and a manufacturer-chart-style spine recommendation with adjustment notes.
Reference
For the long-form on what each number means and the heavy-vs-light arrow debate, see the arrow setup guide.
READ THE GUIDE →The speed this tool estimates starts from your bow's IBO rating — and your real arrow always flies slower than that number. IBO speed vs measured speed. For speed alone, with your string accessories and your bow brand's measured gap, use the arrow speed calculator.
