It will give you a rough idea of how fast an arrow travels after changing the bow from the recommended specifications. We have not done very precise tests to figure this out (we will update this post when we do), however a very close estimate would be to assume the following. *This Calculator Was Developed With The Help of The Ashby Bow Foundation*. The arrow speed calculator makes it easy to estimate the speed of an arrow! Kinetic Energy: 5.55 foot-pounds. move slider or enter value. Arrow Ballistics Calculator Kinetic Energy, Drop, Speed, Momentum, Crossbow Kinetic Energy Chart, Calculations, Hunting Requirements, Crossbow Arrow Drop Charted Test Results. Models at the high end of this spectrum tend to cost a lot so we should be pretty confident the top velocities bring equally impressive results before spending the cash. So the important question right now is: how much does initial arrow speed drop as its weight goes up? Mid-Range Rise; Mid-range rise when sighting in a crossbow is the highest point in the arrows trajectory between the point blank range and the true zero point. The momentum of an arrow is linked to arrow penetration. Power stroke is the distance, in inches, that the string accelerates an arrow down a crossbow's flight rail. Light Blue: Range of efficient arrow weights. The calculator assumes average air density and air viscosity. of draw weight your bow is reduced, raw arrow speed is reduced 15-20 fps. To properly calculate kinetic energy, use the following formula: 1/2 Mass (Arrow Weight in grains divided by 2) x Velocity squared (Arrow Speed x Arrow Speed (in fps from the above formula)) / 225218 - The result of this formula is calculated in foot-pounds (ft-lbs). Meaning that we can increase the speed by simply using a lighter shaft or broadhead, but that would actually reduce the penetration potential of the arrow because momentum is mostly affected by the weight of the projectile. When you pull the trigger most of that PE is transferred to the arrow and converted to kinetic energy (KE), which propels it downrange. For the most accurate results, it is best to use a known speed and known arrow weight under 6 grain per pound to determine your corrected IBO value. Keep in mind that most IBO ratings are not real-world numbers. And of course, most of us operate within a more or less fixed budget and don't enjoy the idea of spending $3k-$4k on one of the latest and greatest models. To learn more about kinetic energy and momentum, visit our kinetic energy calculator and this impulse and momentum calculator. The most critical factor is the IBO speed entered as this is the starting point of the calculations. A heavy arrow will produce a great deal of arrow momentum even at the price of arrow speed, but will eventually go down as arrow speed decreases. One thing to remember is that while kinetic energy provides the impact of your arrow on your intended target, what it doesnt necessarily provide is information on your arrows ability to penetrate and travel through your target. Then, the more draw weight you use to pull, the quicker an arrow will fly and the more kinetic energy it will have. When a crossbow is said to shoot at 300 FPS, that means that, when the arrow leaves the flight rail, it would travel 300 feet in the span of one second if it could constantly maintain its momentum and trajectory. *All data are approximate. When using the calculator above, input your values and then compare them to those values in the tables below. With having said that lets sight these crossbows with a maximum point blank range drop of 3 inches and a mid-range rise of 3 inches. Every 3 grains of additional weight on the bow string will subtract 1 foot per second from the IBO value. Putting it all into perspective. We've created a text where you'll find some of the basics related to IBO speed and how to calculate bow speed. As the arrow moves through space, the kinetic energy drops. Total string accessory weights in grains (peep, tube, silencers, etc.). We sometimes earn a small commission when you click through the affiliate links on our website. This is what we included: The IBO speed is used as a standardized speed rating for bows. Keep reading to learn how to use our calculator and how to optimize your arrow for your hunting needs. Also, make sure to check out our best crossbow rankings for a scoop on the top equipment on the market. How far will it penetrate? Draw length LLL This is the distance that the string is pulled back. Its only from 300 FPS and up that you get enough kinetic energy at all feasible hunting distances (up to 50 yards) to be able to comfortably hunt elk. The values in the table below come from the following bow and its associated settings. For every inch of draw length above 30, add 10 ft/s to the IBO value. And remember, in bowhunting speed is good but it is far from everything. Here are some interesting things to note, based on the kinetic energy chart at the top of this page: #1: Kinetic energy drops are fairly predictable. Keep in mind that most IBO ratings are not real-world numbers. Draw length: A longer draw length creates a longer power stroke than a shorter draw length, allowing the bow to store more energy. As an Amazon Associate we earn from qualifying purchases. To correctly calculate kinetic energy, use the following formula: 1/2 Mass (Arrow Weight in grains divided by 2) x Velocity squared (Arrow Speed x Arrow Speed (in fps from the above formula)) / 225218 The result of this formula is calculated in foot-pounds (ft-lbs). A lighter arrow produces more arrow speed, but an increase in arrow weight (incremented by 25 grains) can increase and eventually decrease arrow kinetic energy. The arrow weight in grains (includes fletchings, wraps, inserts and also. If you open any online store that is selling them, you'd see that the speed of the arrows (measured in FPS or feet per second) that are launched by each listed model is their most prominent feature. For the most accurate results, it is best to use a known speed and known arrow weight under 6 grain per pound todetermine your "corrected" IBO value. This is because the large draw weight imparts more energy to the arrow. So if we have 100 ft-lb initial energy (at 0 yards), at 10 yards you can expect roughly 97-97 ft-lbs. There are several factors that go into the arrow speed equation. Archery Hunting 101: Bow Hunting for Beginners. Spine is measured by the number of inches a shaft deflects (bends) X 1000. The trick is to balance speed (and range finding forgiveness) with arrow mass and penetration potential. The rule of thumb is that for every 10 lbs. Knowing how your arrow speed changes with the increase in arrow weight, you can now easily figure out the new kinetic energy: For instance, if you know your crossbow shoots your current 400 grain arrows with a speed of 400 FPS, our chart above tells you to expect 124.8 ft-lb of kinetic energy at 30 yards. The IBO standard began as a means to regulate archery competitions, but the majority of bow companies have adopted its guidelines to standardize the measurement ofarrowspeed for the purposes of setting bow specifications. Corrected IBO Example - A 70#/29" bow that's rated at 350 fps is has been chronographed at 315 fps with . A longer draw length results in a longer power stroke than a shorter draw length, allowing the bow to store more energy that then is transferred to the arrow. As such we recommend that elk hunters stick to 300 FPS or more. ), Any additional weight on your bowstring (nock loop, peep, etc.). After you've entered these values, the calculator will display the actual arrow speed, momentum, and kinetic energy of the arrow , What is IBO speed? . To achieve this the arrow will actually intersect with the line of sight twice, giving you a dead center hold on the target for many yards without hold-over or hold-under. When you properly sight-in your crossbow for hunting you want to have a flat trajectory, the flatter the better. Speed is good, but whether shooting carbon arrows such as Beman's ICS Crossbow Hunter or Easton's Bloodline, XX75 aluminum or its . But it cannot. You can assume, roughly, that an arrows kinetic energy is reduced by around 3-4% for every 10 yards it travels. Once you have this figure, you can calculate the kinetic energy produced by your bow. Finally, enter the Additional weight on the string if this is known. 500 grain arrows will fly at ~90% of initial speed Nevertheless, most archers do not use these exact parameters. Now, there are a few bows rated at 350+ fps based on the International Bowhunting Organizations (IBO) standard. Your arrows kinetic energy will depend on its speed. Arrow Speed Calculator Bow Manufacturer IBO Speed move slider or enter value ft/sec Draw Weight move slider or enter value lbs Draw Length move slider or enter value inches Arrow Weight move slider or enter value grains Weight Added to String (20gr=peep only, 45gr=peep and tube) move slider or enter value Given enough time, deer would duck in preparation for a big jump. So when you see a certain crossbow rated at 350 FPS, for example, this was most likely calculated using a 400, maybe 425 grain arrow. Kinetic Energy Vs Momentum for Hunting? And your arrow would fly over it or hit a less desirable area, like the spine of the animal. Crossbow Kinetic Energy 200 FPS 225 FPS 250 FPS 1/3 10 20 30 40 50 0 25 50 75 100 125 150 Yards travelled by arrow Kinetic Energy ( In food - pounds) Chart by Visualizer Copyright 2023 | DRCMedia LLC | All Rights Reserved, Scout. IBO Speed (feet per second) When shooting a compound bow, all things being equal, they are: Many bowhunters dont quite understand the complexity behind bow speeds. Please keep in mind that this approach will only give you close estimates, and that it becomes a less accurate the further out we go (I wouldnt suggest using it for anything beyond 70 yards, which is far beyond what youll be hunting from anyway). We are working to correct this issue. How to determine the optimal shooting range for my crossbow? This equation assumes that your bow puts the same amount of energy into each arrow. Every bow gains efficiency a little differently. Example - A 70#/29" bow that's rated at 350 fps is has been chronographed at 315 fps with a 400 grain arrow. Arrow speed is determined by your bows IBO speed (fps), your draw weight (in pounds lbs)), your draw length (in inches), the arrows total weight (in grains), and the weight of what is on the bowstring (in grains) as outlined above. Execute. The table below provides us with a general idea of how much momentum is needed for different types of wild game and it also shows us the arrows penetration capability when coupled with KE. Do you really need a multi range sight for trajectory compensation. For every inch you reduce, the draw length reduces around 10 fps of your bow speed. ), Toughest Game (cape buffalo, grizzly, musk ox, etc. We shot 400 grain arrows from 9 different crossbows, achieving nine different initial speeds ranging from 200 to 400 FPS in 25 FPS increments. Archery & Crossbow Ballistics Calculator: Initial velocity: fps m/s Arrow mass: gr g Angle of departure MOA Shaft length: in cm Shaft diameter: in mm Vane length: in cm Vane height . This is because the IBO speeds are determined under a set of particular conditions: Then, for comparing bow speeds, you'll need tomaintain these factors constant. The arrow speed calculator makes it easy to estimate the speed of an arrow! The same team that conducted the above research suggested a way to calculate the effective range for each bow/crossbow model: Divide the crossbow velocity (in FPS) by 10. The technical storage or access is strictly necessary for the legitimate purpose of enabling the use of a specific service explicitly requested by the subscriber or user, or for the sole purpose of carrying out the transmission of a communication over an electronic communications network. Every bow gains efficiency a little differently. of KE. 1. While KE is an important factor in penetration, momentum is also critical because it determines the arrows ability to push through the target. If it doesn't, adjust your 50-yard pin until it centers on the 50-yard bullseye when you're at full draw. Knowing the rough speed at which your arrow will fly, you can now use our kinetic energy calculator to quickly figure out your arrow's initial kinetic energy. While there are other factors to consider when setting up a compound bow for hunting, all bowhunters want to shoot as fast an arrow as they can with their bow setup. #3:Notall crossbows are suitable for hunting. Let's say you keep the regular. Mike is a Veteran who served 21 years in the U.S. Army and retired as a Sergeant Major from the 5th Special Forces Group. The speed of your arrow will determine how flat of a trajectory your arrow has at short and long distances and how much arc is needed to travel large distances. Bow Manufacturer IBO Speed (ft/sec) Draw Weight (lbs) Draw Length (inches) Arrow Weight (grains) Weight Added to String (grains) (20gr = peep only, 45gr = peep and tube) Arrow Speed 0 ft/sec 0 mph Arrow Kinetic Energy 0 ft-lbs. This does not affect or reflect on our recommendations or opinions. These are calculated as follows: Our arrow speed calculator converts the units automatically. To calculate arrow speed, measure the distance in inches between the two groups of arrows you shot from 20 and 40 yards. The general guideline for this factor is: For every extra inch of draw length increases approximately 10 fps the arrow speed; and. But because these are rarely the conditions under which every archer will be using their bow, then comes the question: what the actual speed of my arrow is? There are a few more things that impact how fast your arrow is traveling after you shoot. Let us see how to use this tool: Begin by indicating the IBO rating in fps in the Bow IBO rating field. The rule of thumb was that for every added inch of draw length, you increase raw arrow speed by approximately 10-15 fps. About the time I reached my fathers then age, technology changed drastically, making it possible for bow companies to achieve 300 fps with a hunting bow. For every 3 grains of additional weight on the bowstring, subtract 1 fps from the IBO value. When an arrow is shot from your bow, its impact, and ability to penetrate and make the kill is based not just on the speed of your bow. Every inch of draw length above 30 will add 10 feet per second to the IBO value. If you want to learn more about momentum and how to calculate it, we have a dedicated momentum calculator that you might enjoy! Now we have what we need to calculate KE: Arrow speed: 240 FPS Arrow weight: 400 grain The formula for calculating Kinetic Energy is: (Arrow weight) x (Arrow speed) x (Arrow speed) / 450,240 Notice that at 250 FPS this value cannot be achieved. Arrow Speed Calculator. With that said, the average efficiency curve utilized for the calculator is based on various bows from APA, Elite, Bowtech, Hoyt, and PSE ranging from 40lbs up to 85lbs. 44 Yards - Maximum Effective Hunting Range. You will find that most modern bows are more than capable of killing most game animals. While it is based on the bow speed IBO specification, you can input the individual settings of your bow. Balanced Bowhunting For whitetail deer this requirement is lower any crossbow 250 FPS and up will be a safe pick. 12.8 330. You should adjust the arrow speed given by the IBO specification according to the following rules: All of these rules can be put in one common equation: You can also use the arrow speed calculator to find the momentum and the kinetic energy of the arrow. Be careful with increasing string weight, as it is equally important to string the bow comfortably. Try our arrow speed calculator below! You should be able to successfully harvest For every inch of draw length under 30, subtract 10 ft/s from the IBO value. A 70#/29 bow that's rated at 350 fps is has been chronographed at 315 fps with a 400 grain arrow. For example, a 500 spine arrow bends .5 inches when the weight is applied. The arrow speed calculator above provides a quick estimation. Arrow speed depends on several factors, including bow string weight, string length, string material, arrow weight, and weather conditions. Which results in easier aiming and thus, in improved precision. Generally speaking, adding 20 grains of overall weight to the string will only deduct about 5 fps off the raw arrow speed. If you know your arrow's weight (in grains) and your arrow's speed (Feet Per Second), then you can use our Kinetic Energy and Momentum calculator above to find out each! Hopefully you find the above charts and information useful in determining what crossbow to buy and how kinetic energy changes based on arrow weight and speed. We strongly recommend reading our detailed kinetic energy tests and guide for more information. , because of the higher momentum at the moment of impact. Most professional bows use the IBO (International Bowhunting Organization) specification. 15.5 300. Reduce the IBO speed until the calculator shows the verified speed of 315; in this case, the correct IBO value would be 346 fps. Let's consider the following example: you are analyzing the bow of IBO 300. This calculator is based on average efficiency gains as arrow weight is increased from 5 grains per pound (IBO). Crossbow Kinetic Energy Chart, Calculations, Hunting Requirements, Compare expected FPS across over 120 crossbows, Arrow Ballistics Calculator Kinetic Energy, Drop, Speed, Momentum, Crossbow Arrow Drop Charted Test Results, Best Hunting Crossbow For The Money in 2020. Bows 5-10 years old will tend to gain efficiency faster than one that is brand new. Which means that if you want to be able to reliably hit live targets at 40 yards, you better have a crossbow that is able to launch arrows at 400 FPS or more. Speed is needed to make the arrow arrive at its target quickly, but arrow speed is not what kills the animals you shoot with your bow. My bow stayed the same: 60-pounds at 27.5-inches of draw. That is defined by an arrows weight, broadhead, and momentum. Momentum is often considered more important for hunting because it can help the arrow maintain its penetration potential. They see a bows IBO speed rating listed, and assume they will get that raw arrow speed, or maybe a little better if they buy that bow. This is a good rough rule to remember in case you need to do some quick on-the-spot kinetic energy calculations in the field. The gravitational constant (g) is the acceleration due to gravity, which is 32.174 feet per second per second at sea level. Kinetic energy (KE) is a measure of an arrows ability to transfer energy upon impact, and a higher KE can result in greater penetration and stopping power. So, the closer you can get to your target, the more kinetic energy your arrow will have. . What allows an arrow to ethically and effectively kill wild game is a combination of kinetic energy and momentum. It's measured by applying an 880-gram weight to the arrow, suspended from the center of the shaft. 2. Crossbow speeds are usually measured in feet-per-second (FPS). The overall weight of the weapon, its balance, arrow weight, ease of cocking, and precision are also important. A feather traveling at 20 mph might sting, or might not even be felt, depending upon how it strikes. Please keep in mind that the values below assume the crossbow configuration is not altered, and that the only change is in arrow weight. In the majority of cases once a peep is added the speed will only be a few fps off but the ratings of some bows are significantly off. Reduce the IBO speed until the calculator shows the verified speed of 315; in this case, the correct IBO value would be 346 fps. The size of the heart/lung area is around 8 inches on a average size deer weighing 120 pounds. Whitetail deer is particularly proficient at doing that. As the arrow travels downrange it is constantly slowing down and dropping toward the ground, the further it travels, the faster it falls to the ground. For a more detailed explanation, check the notes below the calculator. Because there is a huge difference between shooting a deer with a 300 FPS crossbow and a 400 FPS (or faster) model. Thats a massive difference in a hunting scenario. 550 grain arrows will fly at ~85.5% of initial speed Note that the above is valid if speed is NOT increased at the expense of reduced arrow weight. True Zero; True zero when sighting in a crossbow is the second point at which the line of sight intersects with the arrows path in the arrows trajectory arc. The most critical factor is the IBO speed entered as this is the starting point of the calculations. In general, all three methods can be used with equal success as there is little difference in measured speed. During my teens, I spent countless hours with my dad in our archery shop, buildingarrows, tuning bows, and then testing their performance right outside in our backyard. For your reference, an estimated peep only weight is 20 grains, and a peep + tube is 45 total grains. The heavier the arrow is, the faster gravity will pull it toward the ground, but arrows or bolts do not have an even weight throughout. At the time lets call it the Round Cam Epoch the chase was for 200 fps. Momentum: 0.111 slugs. Power stroke is the length between the crossbow's string in its full-draw position and at rest point. Red: Highlights specific speeds in fps and MAX energy (KE and M). Chasing 300 fps? The arrow ballistics calculator below will help you determine your arrow's vertical drop, speed, kinetic energy and momentum, for up to 70 yards out in 10 yard increments.