Arrow Speed Calculator

How to calculate Arrow Speed manually

You can estimate arrow speed manually when you know the bow's IBO speed and key setup values. However, the result remains an estimate.

Formula

A simple physics relationship uses speed, mass, momentum, and kinetic energy:

$KE = \frac{1}{2}mv^2$

$p = mv$

Here, $m$ means arrow mass and $v$ means arrow velocity. Convert units before using standard physics formulas.

Step by step guide

1. Find the bow's IBO speed rating in FPS.
2. Record the draw weight and draw length.
3. Record the total arrow weight in grains.
4. Note any string or cable accessory weight.
5. Adjust the expected speed for your actual bow setup.
6. Use the estimated velocity for physics calculations.
7. Calculate kinetic energy with $KE = \frac{1}{2}mv^2$.
8. Calculate momentum with $p = mv$.
9. Compare the result with a chronograph reading when available.

Practical Example

Suppose an arrow travels at 300 FPS. Convert its speed to meters per second before using SI physics formulas. Since 1 FPS equals 0.3048 m/s, 300 FPS equals 91.44 m/s. If the arrow weighs 0.028 kg, use $KE = \frac{1}{2}(0.028)(91.44)^2$. This gives about 117.1 joules of kinetic energy. Momentum equals $0.028 \times 91.44$, or about 2.56 kg·m/s.

Archery calculator principles

An archery calculator connects bow settings with arrow performance. It uses inputs such as IBO speed, draw weight, draw length, and arrow weight. Physics formulas then help explain speed, kinetic energy, and momentum.

How fast does an arrow travel?

Arrow speed depends on the bow and arrow setup. Many modern bows can produce speeds above 300 FPS under suitable conditions. IBO ratings use specific test conditions, so actual speed can differ.