
pierre berube: hello
it's a very good calculator and a good idea.I am in a archery club and i gived your adress web site at my friends and i put it our web club archery Joe Tapley: Simple and pretty accurate  well done. ten out of ten for the relaxing background image. (anonymous): this is cool! have to measure the distance from eye to scope to make sure it is accurate. But I have the feeling it will. Haller  Denmark: Very interesting program. I am trying to make a ballistic module for bowhunters, like yours but take also Ballistic Coefficient, but I cannot find out how to calculate speed at differents distance. Could you place a link to the formula you have used. Apostolos 22/03/07 : Thanks for your comments! The formula is too complicated to describe here. I used Mathematica to find the solution and it's a formula 4 lines long. Someday I will describe how it is done in a separate page. PS: Joe, you drift program is excellent, it's amazing how good a model of arrow flight you made. Perriswood Dick 30/03/07 : I can see how the algorithm accounts for different arrow size/weight but where is limb/r1ser length and draw weight taken into account RLH Apostolos 01/04/07 : In fact, we don't care about the draw weight but only for the angle difference between the two distances. That uniquely determines the speed of the arrow. Charles 15/05/07 : A very interesting program. Can it be tweaked to allow for sight marks where the distance between the eye and the sight pin changes (ie. bringing the sight in for longer distances?) Apostolos 20/05/07 : I think it could be tweaked for that but I have to find that piece of paper that I had all the equations written on.. I was also thinking of doing another version that could calculate your arrow speed loss per meter given all of your sightmarks. Archimedes 09/06/07 : Hello. Could you please help me figure out how to measure speed of an arrow (point blank) just with draw weight (45 lbs) and arrow weight (385 gr)? I would like to find out my arrow's speed so I could figure out its footpounds of energy. Thank you so much. ben 17/06/07 : this formula is all well and good but what arrow weight is it going off? bestel 17/07/07 : Hi Apostolos and congratulations, great job ! I'd like to translate it in french in order to use it on my club website (it would display your translated page inside a frame). If you're interested, contact me : bestel (at) ifrance (dot) com john r 26/07/07 : i used your speed chart and checked it against many of the known sight marks that i have and it was accurate for all of them. im not the greatest archer but found your formula works for me. THANKS.. Apostolos 03/10/07 : Archimedes: you'd better use one of the other calculator that work on principle of draw weight and arrow weight. Charles: it could be tweaked but it would require two more input variables. When I find some time, I will take a look at it. Roy 14/11/07 : an excellent tool but for one thing!. would it be possible to produce a version with imperial input values for those of us who still live in the stone age...;) Apostolos 21/05/08 : The calculator is back in order! Alper Atmaca 25/05/08 : Its really fantastic!It mesures it very accurately.but i have some questions.is the calculation inculdes the air friction,arrow weight ext?Or its just enought to know the sight difrence between two distance? and do you thing to make this calculator for windows or windows mobile?It would be greate! Dick Baugh 08/06/08 : I use Accurate Sights software from someone in Australia. It also includes compensation for aerodynamic drag. I'll compare its results with yours. Dick Baugh 10/06/08 : Comparison with Accurate Sights software: Matched at 20 and 70 yards. Yours is 4.2 inches low at 10 yards, 8.3 inches high at 50 yards and 44.7 inches low at 80 yards relative to Accurate Sights which includes air drag and distance from eye to arrow. Apostolis 17/06/08 : Dick, thanks for your input. The aerodynamic drag is not taken into account as it impossible to do with only 4 inputs. This program was meant mostly as an easy way to estimate your arrow speed. However if you give the program first your 20m/30m sight marks and then your 70m/90m, you can find out how much speed your arrow loses at longer distances. David Morrish 23/08/08 : As a new archer, I find the sighting info and arrow speed info very helpful, and have recommended the web site to others. Well done! A minor point (very minor) is that in the UK we regularly use distances measured in yards, but sight measurements in cm, so I have to convert the tables to give me data in this mixed format. I am very happy to live with this minor issue, but if you ever found yourself with nothing to do sometime ........!!! Overall, many thanks  a very good reference site. Best wishes, David Morrish HarryMarx 03/09/08 : I did the same thing, but derived formula myself. I get 10 fps more from my formula... Think I can sell it to "make your bow go faster? Nice work Apostolos Jim 09/09/08 : Good job! If you fire two shots using the same pin at different distances and measure the arrow drop, you should be able to determine the speed without knowing distance to the eye, non? Given x1, x2, y1 and y2, determine V0. Dan 21/10/08 : Good calculator however it does not seem to account for decceleration and would only be the average arrow speed from distance one to distance 2, beyond distance 2 your arrow would be constantly deccelerating and thus your extrapolated sight pin settings are slightly off. Steve Brown,archery bowmanship and courtesy 11/11/08 : Hi I read the comments with interest do youhave a similar one for flight shooting. Normally the arrow is shot at 42 to 47 degrees with specialist bows? I have studied balistics but have no luck with the maths. me 08/12/08 : nice thingy... helped me with science fair Apostolis 13/01/09 : Thank you all for your comments. If I find some time, I will update the calculator with your suggestions. Have fun shooting! Hoytfinger 20/01/09 : Thank you for this program! I am shooting field ranges where uphill/downhill calculations depend on arrow speed. You rule!! SamS44 22/03/09 : Can you give us Yards and inches? Joan Smith 05/06/09 : I was asked how fast an arrow travels so I Googled to find out. I found this and thought the very thing I'l just print this out for future questions! Thanks. Robin Of Locksley 19/06/09 : This calculator is quite vague (even for English standards). Arrows of composed of different materials, weights, lengths and the bow being used all play a factor. Most (if not all) archery clubs have a radar device in which you place it near the target and shoot the arrow through it (from about 10 feet away / the arrow will have maximum velocity shortly after it's release). This would be the most accurate way to determine the speed for the particular setup you're using. PS  My father was not a Devil worshiper! Patrick Andresz 17/07/09 : Thank you very much for this nice programm ! It's very helpfull and so helped me to verifie my estimation of the speed of my arrows. I'm not a ballistic engineer, but very curious about how you find the formula. Bye. Hennie 13/08/09 : This is great..... What is the possiblety to put it on excel? Any other web sites to check? Ludek 13/08/09 : Hello, it is also good for bare bow, i tried it. Don Walker 22/09/09 : an excellent tool but for one thing!. would it be possible to produce a version in Yards and diference in site marks settings in mm for old field archers Mark 25/09/09 : I didn't believe it when I looked at the numbers, as the difference between each 5M distance for time and sight markings seemed to be almost constant. But then thinking about the speed of most compounds (300+fps) this would make sense. Just to test the calculator I entered a 10cm difference between to distances  then you can see how the decceleration, gravitational and other forces start to show a nonlinear relationship. Cool. Mark 25/09/09 : Robin or Locksley : The things you mention are constants for the two shots from you bow setup and your arrows. The formular does not need these. Decceleration, gravitational forces and other forces are taken into account by the formular  see my earlier comment. JTC 26/09/09 : As an Engineer by trade, I can see how this method of calculating speed would work. A very cleaver approach. for those of us who use the English system www.metricconversions.org has some nice converstion calculators to convert to metric. Tony Bakes 15/11/09 : As a keen flight archer, this is an invaluable program for seeing what differences small changes in setup will make to the speed (and hence distance) of any bow/arrow combination without having to find a field 1000m long. Well done. Bryan 02/01/10 : Very nice, is this the formulae you used S=SQRT(9.81*x*(d1d2)/(2*h)) where S= Speed x= distance from eye to sight d1/d2= distances h= sight adjustment Anonymus 21/01/10 : ???????? Huh?????? what in the world is 'sight mark setting' and 'eye to sight pin'?????? I'm not in any club and I can shot when I can which is not very much. I am doing this for my science fair project, and I am soooo confused! I am only trying to find an easy way to find out how fast the arrow went... Anonymus 21/01/10 : ???????? Huh?????? what in the world is 'sight mark setting' and 'eye to sight pin'?????? I'm not in any club and I can shot when I can which is not very much. I am doing this for my science fair project, and I am soooo confused! I am only trying to find an easy way to find out how fast the arrow went... SURFELITE 10/02/10 : i am also doing a science fare project for my freshman class. this site is not very helpful. can someone post something/someway to help me fine a way to figure out the acceleration,velocity, and speed of a normal pull back tension of the bow a 45lbs. plz some one help me out this project is due next tuesday and i have nothing.I will keep gettin on this site to see if anyone has answered my question thank you. SURFELITE 10/02/10 : *also the arro need to either be a carbon/graphite or aluminum arrow thank you yet again f 05/03/10 : fffff HansErich Dunker  Germany 08/06/10 : It´s a nice helpful tool and incredible accurate  thanks Deano 06/08/10 : I checked the results given by your program, aginst archers advantage. All the results are fairly accurate, congrats on a job well done. paul f 08/09/10 : i have access to a speed gun would that work too kayla 10/09/10 : that is cool Li 01/10/10 : This calculator works pretty well. Confirmed the sight markings at all distances listed. Only the 18m was off by about 0.2cm, probably due to parallax error not taken into account matienchi 06/11/10 : I would assume that the speed calculated is the average speed of the arrow from the bow to the target, not the speed of the arrow leaving the bow. Am I correct? Haller  Denmark 30/11/10 : Hi, I solved it, so now it is possible to se speed at any distance. You can see the result on http://www.haller.dk/bow%20and%20arrow%20ballistic.swf where I have tried to make en US version. Thank you for the inspiration 30/11/10 : its stupid Rob 16/12/10 : Check this out. Very close to chronograph measurement. http://www.backcountrybowhunting.com/articles/tools.php Franck Kinfack 17/12/10 : amazing it is the best calculating site ever!!!!! dakoda 05/01/11 : what kind ok arrows are there hi 14/02/11 : did not work i am angry :( apostolis 29/03/11 : Thanks for all your feedback! I'm glad many of you like this small application. To address some comments: 1) the speed measured is the average speed of the arrow in flight 2) the formula is not simply the second order ballistic equation but something rather more complex and difficult explain here. enclosed 14/04/11 : dont under stand Chris 01/05/11 : Sorry to be negative, but the key assumption is false so the math is faulty. The change in angle does not provide a unique solution. Arrows of different weights and drag could follow different paths and still end up passing through the same two points by varying the initial speed. Other that at those two points, the trajectories could differ greatly. You need at least one more data point or the initial speed for a decent estimate. Tray colder 08/05/11 : Can u do it in yards? Sebastian Suter 13/06/11 : Hello, does anyone have a link to a formula to use it for "offline" calculations? Phil 02/07/11 : When I had a chance to shoot through a chronograph, I found the calculated speed to be within 1 fps. I think that's pretty good! Martin Vargas 26/09/11 : Hi Guys this is awesome,I try it last weekend and it works bery well thaks for the effort to debelop this tool. Bido 01/12/11 : Have taken print out of predictions and will try the settings. Will post further comment on results of shooting. Cheers veerle boden 10/12/11 : heel goed Samantha 13/12/11 : why would any of this matter? Ted 15/01/12 : This is really awesome. Don't know how soon I'll be able to get outside to see how accurate the approximation is for 90m sight setting, but if this is right, maybe I can reach 90m without having to step up to a heavier set of limbs! Asha 21/02/12 : This is really good and I think it is quite accurate could you please let me know the formula? Asha 21/02/12 : This is really good and I think it is quite accurate could you please let me know the formula? I dont mind if it is complicated if you could email it that would be great (asha_aisling@eircom.net) Anne Marie 16/07/12 : Nice calculation. Perfect for long distance. some differences for shorts (under 20m). I suppose that the differences from one shooter to the other becomes noticeable. Serge Theriault 17/08/12 : Better and more accurate than charts that I've found on the internet. Whit this calculator it seems you could figure out your speed with any two given distances (short at 10m20m, like 20m 40m). abdul 22/11/12 : me no deer =( Scott Reynolds 28/01/13 : Baffling. Is this thing broken? Whatever values I enter, the result is a linear chart  and we know that's not correct. William Hunt 18/02/13 : Hi. This really useful! Perhaps you think of making an app for the iPhone / Android...? Hartmut 20/03/13 : Very good and practical device to calculate the approximate value of the medium arrow speed. Robbo 11/05/13 : Hi appears really good need to try it out but i guess it will be near on bang on, just one thing any chance the yrds chart can give cm readings as most sights now are in cm? Sorry just had that thought, it might help people in case they dont realise its in inches they may be using a cm bar. Mant thanx & Best wishes Robbo Robbo 11/05/13 : by the way making an app for the mobile phone andr & iphone & windows would be so cool, people could take it to the range why not contact the big archery companys (hoyt bear, easton mathews) see if they will sponsor you or buy it from you. ? good luck make some money dude, but good that you are serving the community. Robbo Torcrayth 06/08/13 : I love the fact that you can give two distances rather than the set 20m & 60m I found in numerous other places.... I'd really like to have the math behind this so I can put it into a spreadsheet along with kinetic calc so I can see the difference between recurve and compound damage to a target!! Tyler 23/01/14 : what is the draw weight? Nicole 09/03/14 : What is a sight pin? Athar 18/05/14 : Any chance you can post one for yards? A Sight Pin is the center of the aperture you look through when you have your arrow drawn. It its attached to the sight that is bolted to the handle or riser of a bow. The sight pin is in direct line of sight and usually hovers over or obstructs the view of the point where you want your arrows to land on a target. General Draw Weight is the peak amount of weight you will pull while drawing the bow. Typically, the weight is printed on the limbs of a bow. Specific draw weight can be measured with a bow scale, which will also tai into account the length you are pulling the string back to anchor it, or your Draw Length. Ten_Zen 20/05/14 : I am a physics major and I use Mathematica. I would love to see the formula! Is there any way you can send me the .nb file so I can play around with it? Here's my email, thanks! phigene777@gmail.com DDA 23/06/14 : So I got new arrows, changed my sight block, adjusted arrow rest, etc etc, then had to go and soot the next day. All I have was my previous marks, so I shot both sets of arrows @ a 20M target, Used my 50M and 60M marks with original arrows, found the difference @ 20M then extrapolated a possible 50M and 60M mark for new arrows. Put them in the calculator. 2 things happened. 1) I was damn lucky to get the new 2 marks almost spot on (just super lucky with all the changes) 2. The marks that the calculator gave me were also so damn close it's not worth mentioning the adjustments I had to make. Thank you very much for taking the time to do this, and sharing it. tyler 15/09/14 : this is a awesome site nd i like the way it tells me everything. Ethan 15/09/14 : this is a terrible site. it sucks Jerry 15/09/14 : this is the worst freaking site ever man this is horrible Cave Johnson 25/04/15 : Can you add metric sight markings to the imperial distance table? also can you provide the formulas or spreadsheet used to calculate them? thanks! Fabián 18/05/15 : Great job! Kit Sun 13/12/15 : Exactly what i'm looking for. Zero in for 2 distances and to be able to calculate the rest of the sight marks 