Arrow Speed Calculator
Convert a bow's IBO rating into your real arrow speed. Adjust draw length, draw weight, arrow weight and string accessories to estimate true FPS.
Your setup
Shaft + insert + point + nock + fletching. Most hunting arrows weigh 400–500 grains.
Peep, D-loop, nock set and silencers. A peep plus D-loop is typically around 10 grains.
Estimated real-world arrow speed
About 49 fps below the IBO rating.
Where your speed is lost
IBO Speed vs. Real-World Speed
Every compound bow is sold with an IBO or ATA speed rating. That number is measured at a standard setup: a 30-inch draw length, 70-pound draw weight and a 350-grain arrow, with nothing on the string. Very few hunters shoot that setup, which is why your chronograph almost always reads lower. This Better Outdoors calculator works backward from the IBO rating using common rules of thumb:
| Change from IBO setup | Typical effect on speed |
|---|---|
| Each inch of draw length under 30" | About −10 fps |
| Each pound of draw weight under 70 lb | About −2 fps |
| Each 3 grains of arrow weight over 350 gr | About −1 fps |
| Each 3 grains added to the string | About −1 fps |
Does Arrow Speed Matter for Hunting?
Speed flattens trajectory, which makes misjudged yardage less costly. But speed is not everything: a heavier arrow carries more momentum, penetrates better and is quieter. Most whitetail hunters do well anywhere from 260 to 300 fps with a 400–475 grain arrow. Check what your setup delivers in our kinetic energy calculator, and see how draw length shifts speed in our draw length adjustment guide.
Measure and tune your speed
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Frequently Asked Questions
How do I calculate arrow speed from IBO?
Start with the IBO rating, subtract about 10 fps per inch of draw length under 30 inches, about 2 fps per pound under 70 pounds, and about 1 fps for every 3 grains of arrow weight over 350 grains and every 3 grains added to the string.
Why is my arrow slower than the advertised speed?
IBO speed uses a 30-inch draw, 70-pound weight and a light 350-grain arrow with a bare string. Shorter draw lengths, lower weights, heavier arrows and string accessories all reduce speed.
What is a good arrow speed for deer hunting?
Most hunters are well served between about 260 and 300 fps with a 400 to 475 grain arrow. Accuracy and shot placement matter far more than a few extra fps.
Does a heavier arrow lose speed but gain energy?
A heavier arrow is slower, but it usually keeps slightly more kinetic energy and noticeably more momentum, which helps penetration.
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