Archery Calculators
Free archery calculators: arrow spine selector, draw weight, arrow flight speed, kinetic energy, momentum, FOC percentage, and more.
Spine, arrow weight, speed and sighting numbers. 11 calculators for compound, recurve and traditional shooters. Firearms sit under Shooting Sports.
Arrow spine is the one to settle first, and the convention behind it trips up nearly everyone. Spine is a deflection measurement, so a lower number means a stiffer shaft. Everything that loads the arrow harder pushes you toward that lower number: a longer draw, a heavier point, a more aggressive cam. Subtract roughly 5 from the spine figure per inch of draw beyond 28, and about 25 per extra 25 grains of point weight. Recurve shooters have a second trap waiting, since a bow’s rated weight is measured at a 28 inch draw and the real figure shifts about 2.5 lb per inch either side of it.
Front of Centre (FOC) puts most arrows between 7 and 15%. Target work sits low for a flatter trajectory, broadheads sit high for penetration, and the two bands overlap on purpose, because a 10.5% arrow genuinely suits both.
Sight tape and point-of-impact pages assume spine is already right. Tuning around a wrong shaft chases groups that will never close.
Bow String Stretch and Replacement Calculator
Track bow string stretch from shot count, draw weight, and material. Get FPS loss estimate and replacement schedule for compound, recurve, and longbow strings.
Arrow FOC (Front of Center) Balance Calculator
Calculate the Front of Center (FOC) balance point of your arrow. Find your FOC percentage and see if it's in the optimal range for accuracy and penetration.
Archer Draw Length Calculator
Calculate your correct bow draw length from your wingspan or arm span. Proper draw length is the foundation of accuracy, consistency, and safe form.
Archery Draw Weight for Game Calculator
Check if your bow draw weight meets the minimum for ethical hunting. Find recommended draw weight for different game animals.
Archery Point of Impact Shift Calculator
Calculate how much your point of impact moves per click of sight adjustment. Works for recurve, compound, and Olympic archery sights.
Archery String Length Calculator
Calculate the correct bowstring length for your recurve or longbow from bow length. Covers AMO string length formula and string material stretch allowances.
Arrow Flight Time Calculator
Calculate the time your arrow takes to reach the target at a given distance and initial speed. Useful for instinctive shooting and gap shooting technique.
Arrow Kinetic Energy Calculator
Calculate arrow kinetic energy from mass and velocity. See whether your arrow has enough energy for ethical hunting or target shooting performance.
Arrow Spine Calculator
Find the correct arrow spine stiffness for your bow draw weight, draw length, and arrow length. Avoid poor arrow flight and inconsistent accuracy.
Bow Sight Tape Calculator
Calculate bow sight tape marks for each distance. Enter your zero distance mark position and arrow speed to generate a full sight tape for field archery.
Total Arrow Weight Calculator
Calculate the total arrow weight in grains from shaft GPI, insert, point, nock, and fletching weights, with build categories from 3D speed to heavy hunting.