Understanding This Calculator
Kinetic energy tells you how much force an arrow can deliver on impact, while momentum measures its ability to maintain penetration through resistance like hide, muscle, and bone. Both matter for ethical, effective hunting shots — energy alone doesn’t guarantee penetration if momentum is low.
Enter your arrow’s total mass in grains (including point, insert, vanes, and nock) and its measured speed in feet per second, ideally from a chronograph reading taken a few feet from the bow.
- mass total arrow weight in grains
- speed arrow velocity in feet per second (fps)
| Kinetic Energy | Suitable Game |
|---|---|
| Under 25 ft-lbs | Small game |
| 25 – 41 ft-lbs | Medium game (deer) |
| 42+ ft-lbs | Large / dangerous game |
Frequently Asked Questions
Is kinetic energy or momentum more important for hunting?
Both matter. KE reflects total delivered energy, while momentum better predicts penetration depth, especially with heavier, slower arrows. Many bowhunters favor a heavier arrow with solid momentum over a light, fast one with high KE but poor penetration.
How do I get an accurate speed reading?
Use a chronograph positioned a few feet in front of the bow, shoot several arrows, and average the readings. Speeds measured by manufacturers (IBO/ATA ratings) are typically higher than what you’ll get from your actual hunting setup.