Arrow Speed Calculator

Written by Great Medico

Updated September 25, 2026 •2 min read

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Problems involving arrow speed can look simple until units, signs, or hidden assumptions start changing the answer. For arrow speed, motion calculations become useful when the inputs and assumptions are kept explicit. A clean result can help you compare scenarios quickly, but the number only means what the underlying kinematic or drag model allows.

What this calculator does

The Arrow Speed Calculator evaluates the relationship behind arrow speed and reports actual arrow speed from the values entered on the page. Supporting values, where available, help you see the intermediate physics instead of treating the headline number as a black box.

How to use it

Start with the fields that drive the current calculation: Bow IBO rating, Draw length of the bow, Peak draw weight. Enter values in the units shown beside each field; the page converts supported units before applying the formula. Keep signs and angles consistent with the labels, then read the headline result together with any supporting metrics rather than copying the number without its unit.

How the calculation works

The current model starts from the bow’s IBO speed and applies the page’s IBO-style adjustments: draw length changes speed relative to 30 inches, added string weight reduces speed, and an arrow heavier than 5 grains per pound of draw weight receives a weight penalty. The result is reported in feet per second, with supporting momentum and kinetic energy.

Example

Using the default example on the page (Bow IBO rating = 320 ft/s; Draw length of the bow = 28 in; Peak draw weight = 70 lb), the calculator returns actual arrow speed of 300 ft/s. Change one input at a time and compare the direction of the change with the formula above; that is a quick way to catch a wrong unit, sign, or selected method before you rely on the number.

How to interpret the result

On the Arrow Speed Calculator, read the actual arrow speed together with the direction, time, or supporting trajectory values shown on the page. A physically reasonable result should respond consistently when you change speed, angle, height, drag, or mass according to the formula. Always keep the displayed unit attached to the number.

Limitations and notes

This is an IBO-style estimate, not a chronograph reading. Bow efficiency, cam design, arrow construction, release technique, temperature, string condition, and manufacturer test assumptions can shift real speed. Use measured chronograph data when exact arrow velocity matters.