Arrow Speed Calculator
Calculate arrow velocity, momentum, and kinetic energy based on bow specifications and arrow parameters
Calculate Arrow Speed
International Bowhunting Organization speed rating
Distance you draw the bowstring back
Maximum force required to draw the bow
Total weight of arrow including tip and fletching
Weight of accessories attached to bowstring (nocking point, silencers, etc.)
Arrow Speed Results
Formula used: v = IBO + (L-30)×10 - W/3 + min(0,-(A-5D)/3)
Adjustments: Draw length: 0 fps, String weight: -0.0 fps, Arrow weight: 0.0 fps
Speed Analysis
Example Calculation
Typical Hunting Setup
Bow IBO Rating: 300 fps
Draw Length: 32 inches (2 inches over standard)
Draw Weight: 70 lbs (standard)
Arrow Weight: 400 grains (heavier than standard 350)
String Weight: 5 grains (nocking point + silencers)
Calculation Steps
v = 300 + (32-30)×10 - 5/3 + min(0,-(400-5×70)/3)
v = 300 + 20 - 1.67 + min(0,-(400-350)/3)
v = 300 + 20 - 1.67 + min(0,-50/3)
v = 300 + 20 - 1.67 - 16.67
Final Speed: 301.7 fps
IBO Standard Conditions
IBO ratings are measured under these standard conditions. Any deviation affects actual arrow speed.
Speed Adjustment Rules
Draw Length
±10 fps per inch from 30″
Arrow Weight
-1 fps per 3 grains above 5×draw weight
String Weight
-1 fps per 3 grains added
Archery Tips
Heavier arrows penetrate better but fly slower
Faster arrows have flatter trajectories
Kinetic energy is crucial for hunting effectiveness
Proper arrow spine is essential for accuracy
Understanding Arrow Speed Physics
What Affects Arrow Speed?
Arrow speed depends on several key factors that work together to determine the final velocity. Understanding these factors helps optimize your bow setup for specific purposes.
Key Factors
- •Draw Weight: Higher draw weight stores more energy
- •Draw Length: Longer draw stores more energy
- •Arrow Weight: Heavier arrows move slower but carry more energy
- •Bow Efficiency: How well the bow transfers energy to the arrow
IBO Formula Explanation
v = IBO + (L-30)×10 - W/3 + min(0,-(A-5D)/3)
- v: Actual arrow speed (fps)
- IBO: Bow's IBO rating (fps)
- L: Draw length (inches)
- W: Additional string weight (grains)
- A: Arrow weight (grains)
- D: Draw weight (pounds)
Note: This formula is empirical and provides good estimates for most modern compound bows.
Kinetic Energy vs Speed
While speed is important for trajectory, kinetic energy determines the arrow's ability to penetrate targets. For hunting, a balance of speed and kinetic energy is crucial.
Target Archery
Prioritize speed for flatter trajectory and reduced wind drift
Hunting
Balance speed and kinetic energy for optimal penetration