Arrow Speed Calculator

Model your bow's performance by estimating arrow velocity, KE, and momentum.

Translate your bow's IBO rating and unique component setup into a practical performance estimate, including speed (FPS), kinetic energy, and momentum.

Practical Examples

See how different setups affect arrow performance.

Standard Hunting Setup

hunting

A common configuration for hunting whitetail deer, balancing speed and power.

IBO: 340 fps, DW: 65 lbs, DL: 29 in

AW: 425 gr, Added: 25 gr

Speed-Focused 3D Archery

speed

A lightweight setup designed for a flatter trajectory in 3D archery competitions.

IBO: 350 fps, DW: 70 lbs, DL: 30 in

AW: 350 gr, Added: 5 gr

Heavy Arrow for Large Game

heavy

A setup focused on maximizing kinetic energy and momentum for large, tough animals like elk or bear.

IBO: 330 fps, DW: 70 lbs, DL: 29.5 in

AW: 500 gr, Added: 20 gr

Beginner/Youth Bow Setup

beginner

A typical setup for a beginner or youth archer with lower draw weight and length.

IBO: 310 fps, DW: 50 lbs, DL: 27 in

AW: 380 gr, Added: 15 gr

Other Titles
Understanding the Arrow Speed Calculator: A Comprehensive Guide
Dive deep into the physics of archery and learn how to optimize your bow's performance for any scenario, from target shooting to big game hunting. This guide will walk you through every aspect of arrow ballistics.

What is the Arrow Speed Calculator?

  • Core Concepts
  • Why It Matters
  • IBO Standard vs. Chronograph
The Arrow Speed Calculator is a powerful digital tool for modern archers and bowhunters. It mathematically models your bow's performance to estimate your arrow's velocity (speed), kinetic energy (power), and momentum (penetration potential). Instead of relying on guesswork or expensive equipment, you can input your specific setup details—bow model, draw weight, arrow components—and receive a highly accurate performance profile. This is foundational for making informed decisions about your gear, ensuring ethical hunting, and achieving greater accuracy.
Why Is Arrow Performance So Critical?
Understanding your arrow's performance is about more than just speed. A flat trajectory, governed by speed, makes aiming over unknown distances much more forgiving. Kinetic energy determines if your arrow has enough power to be effective on a target or game animal. Momentum is the key to penetration, especially when encountering tough hide or bone. Mastering these three elements allows you to build an arrow setup perfectly tailored to your objective, whether it's winning a 3D tournament or pursuing the hunt of a lifetime.
The IBO Standard: A Manufacturer's Benchmark
The IBO (International Bowhunting Organization) speed is a standardized rating used by manufacturers. It's a 'laboratory' speed, measured under perfect, consistent conditions: a 70-pound draw weight, a 30-inch draw length, and a 350-grain arrow with nothing on the string. It's a useful benchmark for comparing the raw potential of different bows, but it's not a real-world speed. This calculator's primary function is to translate that benchmark IBO speed into a practical, real-world estimate based on your personalized setup.
Calculator vs. Chronograph
A chronograph is a device that physically measures the speed of your arrow as it passes through its sensors. It provides the most accurate 'true' speed reading. This calculator, on the other hand, provides a highly accurate estimate based on a proven mathematical model. While a chronograph is the gold standard for measurement, this calculator is a free, convenient, and powerful tool for planning, experimenting with different setups virtually, and understanding the 'why' behind your performance numbers without needing to own a chronograph or fire a single shot.

Key Performance Metrics Explained:

  • Velocity (FPS): Determines the arrow's flight time and trajectory. Higher speed equals a flatter path.
  • Kinetic Energy (ft-lbs): The 'work' your arrow can do on impact. A critical measure for hunting effectiveness.
  • Momentum (slug-ft/s): The best indicator of an arrow's ability to penetrate. Mass-driven and crucial for large game.
  • Front of Center (FOC): The percentage of the arrow's total weight that is in the front half. Higher FOC improves flight stability and penetration but is a separate, more advanced calculation.

Step-by-Step Guide to Using the Calculator

  • Gathering Your Data
  • Inputting Values
  • Interpreting Results
Using the calculator is simple, but the accuracy of its output is directly proportional to the accuracy of your input. Follow these steps meticulously for the most reliable performance estimate.
1. Find Your Bow's IBO Speed
This value is the cornerstone of the calculation. Check your bow's original manual, the manufacturer's official website, or archery forums for your specific bow model and year. Do not use speeds from similar models, as they can vary significantly.
2. Measure Your Actual Setup Accurately
Avoid guesstimating. Use proper tools: A bow scale for peak draw weight. An AMO-standard measuring tape for draw length. A digital grain scale for your fully assembled arrow (including the point, insert, nock, and fletchings) and also for your string accessories (peep sight, D-loop, silencers). Every grain matters.
3. Enter Data and Avoid Common Pitfalls
Double-check your numbers before hitting 'Calculate'. A common mistake is entering arrow weight without the point, or forgetting to add the weight of string silencers. Ensure you are using the correct units (fps, lbs, inches, grains). Remember to input the weight of any added string components, as this can easily account for a 5-10 FPS loss.
4. Analyze, Interpret, and Apply the Results
The results provide a complete ballistic profile. Is your Kinetic Energy sufficient for your target animal? (See our table below for reference). Is your momentum high enough for deep penetration? If you are a target archer, does the estimated speed give you the flat trajectory you need? Use these numbers to validate your current setup or to plan your next one.

Game Animal Kinetic Energy Recommendations (Minimums):

  • Small Game (Rabbits, Squirrels): 25 ft-lbs
  • Medium Game (Whitetail Deer, Antelope): 40 ft-lbs
  • Large Game (Elk, Black Bear, Wild Boar): 50 ft-lbs
  • Toughest Game (Cape Buffalo, Grizzly Bear, Moose): 65+ ft-lbs

Real-World Applications and Setup Optimization

  • Ethical Bowhunting
  • 3D & Target Archery
  • Advanced Tuning
This calculator transitions from a theoretical tool to a practical asset when you use it to make real-world decisions and improvements.
Building an Ethical Hunting Setup
Responsible hunting is paramount. Use the calculator to build a setup that ensures a quick, humane harvest. This often means prioritizing momentum and kinetic energy over raw speed. A heavier, more stable arrow might be slightly slower, but its ability to penetrate vitals effectively, even on less-than-perfect angles, is what counts. Cross-reference your calculated KE with established minimums for your quarry.
Gaining a Competitive Edge
In 3D and field archery, distances are often unknown. A faster arrow provides a flatter trajectory, making errors in yardage estimation less critical. A misjudged 35-yard shot that is actually 40 yards will have a much smaller point-of-impact difference with a 300 FPS arrow than a 260 FPS one. Use the calculator to see how different arrow weights and draw weight adjustments can increase your speed and shrink your groups at distance.
Virtual Tuning and Experimentation
Before you spend a dime on new arrows, points, or even a new bow, you can model the changes here. How much KE will you lose if you switch to a lighter arrow to gain speed? Is it worth increasing your draw weight by 3 lbs for an extra 5 FPS? This tool lets you conduct countless 'what-if' scenarios to find the optimal balance of speed, power, and penetration for your specific goals.

Common Misconceptions & Archery Myths

  • Speed vs. Power
  • IBO vs. Reality
  • The Heavy Arrow Debate
The world of archery is filled with long-standing myths and marketing hype. Let's use physics to separate fact from fiction.
Myth: Speed is the Most Important Metric
This is the most common myth. Marketers love to sell bows based on high FPS numbers. While speed is exciting and creates a flatter trajectory, it is not the best measure of a hunting arrow's effectiveness. An ultralight arrow traveling at blistering speed can have very low momentum, leading to poor penetration on game. The ideal setup is a balance of all three metrics, often leaning towards higher momentum for hunting.
Myth: My Bow Shoots at its Advertised IBO Speed
As discussed, this is almost never true for a typical hunting or target setup. The IBO rating is a standardized, stripped-down measurement. Your real-world setup with a peep sight, D-loop, heavier arrow, and potentially lower draw weight or length will always be slower. This calculator is designed specifically to bridge the gap between the advertised IBO fantasy and your on-the-range reality.
Debate: Are Heavy Arrows Always Better?
Not always, it depends on the application. For hunting large, tough animals, a heavy arrow (and high momentum) is almost universally recommended for its penetration capabilities. Heavier arrows are also quieter to shoot and more forgiving. However, for long-range target shooting or 3D archery where trajectory is paramount, a lighter, faster arrow can be the better choice. There is no single 'best' arrow weight; it's about matching the arrow to the intended purpose.

Expert Tip:

  • For hunting, many seasoned archers recommend a minimum of 0.3 slug-ft/s of momentum for deer-sized game and upwards of 0.4 slug-ft/s for larger animals like elk.

Mathematical Derivations and Formulas

  • IBO Adjustment Model
  • Kinetic Energy Formula
  • Momentum Formula
For the technically-minded, here are the formulas and adjustment factors the calculator uses. While the model is a robust estimate, remember that real-world results can have minor variances due to string wear, cam timing, atmospheric conditions, and other small factors.
The Speed Estimation Model
The calculator employs a linear adjustment model based on industry-standard approximations:
- Base Speed: Starts with the bow's IBO rating.
- Draw Weight Adj: Subtracts ~1.5 FPS for every pound BELOW 70 lbs. Adds ~1.5 FPS for every pound ABOVE 70 lbs.
- Draw Length Adj: Subtracts ~10 FPS for every inch BELOW 30 inches. Adds ~10 FPS for every inch ABOVE 30 inches.
- Arrow Weight Adj: Subtracts ~1.5 FPS for every 5 grains ABOVE 350 grains. Adds ~1.5 FPS for every 5 grains BELOW 350 grains.
- String Weight Adj: Subtracts ~1 FPS for every 3 grains of mass on the bowstring.
Kinetic Energy (KE) Formula
Kinetic energy represents the energy an object has due to its motion. In archery, it's a good measure of the 'shock' and damage potential of an arrow. The formula is:
KE = (Arrow Weight in grains × (Speed in FPS)²) / 450,240
The constant 450,240 reconciles the units (grains, feet per second) to produce the standard output of foot-pounds (ft-lbs).
Momentum (p) Formula
Momentum is mass in motion (p = mv) and is a superior metric for predicting an arrow's ability to continue moving through a resistant medium (like an animal's tissue and bone). The formula is:
p = (Arrow Weight in grains × Speed in FPS) / 225,218
The constant 225,218 converts the units to produce the standard output of slug-feet per second.

Important Note on Model Accuracy:

  • This model is highly accurate for most modern compound bows but may be less precise for very old bows, traditional bows, or crossbows which use different mechanical systems.