Two key aspects of bowhunting performance are kinetic energy, and momentum of the arrow. Kinetic energy is simply the “power potential” of the arrow at the target, based on its mass weight and speed. Momentum can be thought of as the ability to put that power to work, penetrating the target.
Light weight arrows at high velocity may have lots of kinetic energy, but generally, heavier arrows generally provide greater momentum, and this means deeper and more reliable penetration. The trick is to balance speed (and range finding forgiveness) with arrow mass and penetration potential.
To calculate your arrow’s kinetic energy you need to know two variables: 1) your total finished arrow weight in grains, and 2) the velocity of your arrow. Arrow weight is measured on a grain scale and arrow velocity is found by shooting through a chronograph. To measure these variables, visit your local qualified archery pro shop.