Had these recommendations for a number of years:

Small game - 20 to 30 ft-lbs is sufficient. Some states may have a minimum requirement.

Deer - 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.

Bear - We would recommend at least 50 ft-lbs of energy for black bear and brown bear.

Elk @ Caribou - 50 ft-lbs or more would be recommended for this type of game. Mostly because the shots may be at further distances.

There are a number of websites you can use to calculate your energy. You'll need to know the weight in grains of your arrow and the speed of that arrow measured through a chrono.