⚡ Kinetic Energy Calculator
Enter total arrow weight and speed to calculate kinetic energy (ft-lbs) and momentum — then see which game animals your setup is suited for.
How to use this calculator
- Weigh a complete arrow (with point) in grains.
- Chronograph your arrow speed, or use your bow’s IBO minus typical losses.
- Read kinetic energy in foot-pounds and momentum in slug·fps.
Frequently Asked Questions
How much kinetic energy do I need for deer?
The commonly cited guideline is 25–41 ft-lbs for whitetail deer. Most modern compounds at 60 lbs draw weight comfortably exceed this.
How is arrow kinetic energy calculated?
KE = (arrow weight in grains × velocity in fps²) ÷ 450,800. The divisor converts grains and fps into foot-pounds.
Is momentum or kinetic energy more important?
KE is the standard benchmark, but momentum better predicts penetration on heavy game — which is why elk hunters favor heavier arrows even at lower speeds.