Kinetic energy is the energy produced by a certain object in motion. Kinetic energy is an expression of the fact that a moving object can do work on anything it hits or comes into contact with. In archery kinetic energy of an arrow is measured in foot pounds (ft lbs)and describes the force or energy that the arrow creates when it comes into contact with the target or animal.
When bow hunting it is essential that your arrow is generating enough kinetic energy in order to efficiently kill and in most cases get a pass-through on the animal. If your arrow does not generate the kinetic energy needed for the animal the arrow will not properly penetrate and kill it and will more than likely end up injuring it and causing the animal to get away from you.
Below the calculator table portion, is a general rule of thumb when it comes to animals you’re hunting and the amount of kinetic energy that is needed. *It is important to note that these values are just generalized and differ between different states/provinces.
Small game- 20 to 30 ft-lbs is sufficient. Some states may have a minimum requirement.
Medium Game – For whitetail, mule deer, black tail and the like it is recommended to have at least 40 ft-lbs. Certainly a well placed arrow with slightly less than that may do the job.
Big Game- 50 ft-lbs or more would be recommended for this type of game. Mostly because the shots may be at further distances.