Arrow Speed Calculator
Arrow speed depends on your bow's IBO rating adjusted for your actual setup. A 330 IBO bow shot at 28" draw, 60 lbs, with a 400-grain arrow produces roughly 260 fps, well below the rated 330. This calculator applies the standard industry adjustments so you can estimate your real-world arrow speed and the resulting kinetic energy and momentum.
Bow manufacturers rate speed using the IBO standard: 30" draw length, 70 lbs draw weight, 350-grain arrow, and a bare bowstring. Your actual speed will differ based on these adjustments:
Speed Adjustments from IBO
- Draw length: Subtract ~10 fps for each inch below 30" (add for each inch above)
- Draw weight: Subtract ~2 fps for each pound below 70 lbs (add for each pound above)
- Arrow weight: Subtract ~1 fps for each 5 grains above 350 (add for each 5 below)
- String accessories: Subtract ~1 fps for each 3 grains of peep, D-loop, silencers, etc.
Hunting Kinetic Energy Guidelines
- Small game (rabbits, turkeys): 25+ ft-lbs
- Medium game (whitetail, antelope): 40+ ft-lbs
- Large game (elk, moose): 55+ ft-lbs
- Dangerous game (grizzly, cape buffalo): 65+ ft-lbs
Momentum matters more than raw energy for penetration. An arrow with high momentum punches through bone and hide more reliably. Most bowhunting experts recommend at least 0.40 slug-ft/s for whitetail and 0.50+ for elk.
The minimum safe arrow weight is 5 grains per pound of draw weight. Shooting lighter arrows risks damaging your bow (dry-fire effect) and produces excessive vibration.