Archery Kinetic Energy Chart by Game Class
The short answer: 25 ft-lb for deer, 42 for elk and black bear, 65 for cape buffalo and grizzly. Those three are Easton's charted figures. We add 15 ft-lb for small game and 50 for moose, and we label those two as ours rather than dressing them up as industry standard.
There is a problem with every other page that answers this question: the chart they are all quoting no longer exists. Easton's game-class kinetic-energy table was on eastonarchery.com through 2011, disappeared from the site in January 2012, and has returned a 404 since April that year. Nothing equivalent appears on Easton's current kinetic-energy page. The numbers survived by being copied from forum post to forum post for fourteen years, usually with no source and sometimes with the bands quietly altered.
So this page does two things. It reproduces the original chart with a citation you can check, and it publishes the floors we actually grade against — marked so you can tell which are Easton's and which are our judgement.
The floors we grade against
| Game class | KE floor | Typical mass | Where the number comes from |
|---|---|---|---|
| Small game | 15 ft-lb | under ~60 lb | Sparrow's judgement |
| Deer / antelope | 25 ft-lb | ~100–400 lb | Easton, charted |
| Elk / black bear / boar | 42 ft-lb | ~150–900 lb | Easton, charted |
| Moose and heavy thin-hided game | 50 ft-lb | ~800–2,000 lb | Sparrow, derived |
| Cape buffalo / grizzly | 65 ft-lb | ~1,000 lb and up, or armoured | Easton, charted |
These are floors, not grades. Clearing 42 ft-lb does not make an arrow good for elk; it means energy is no longer the thing standing in your way. Tune and shot placement decide the outcome. An arrow that clears every floor and flies badly kills nothing.
The original Easton chart, as published
Reproduced from Easton Technical Products' own site. Verified present in five Internet Archive captures between 3 June 2011 and 17 December 2011 (© 2011 Easton Technical Products), absent from the 17 January 2012 capture, and 404 from 28 April 2012 onward.
| Kinetic energy | Easton's stated usage |
|---|---|
| 25 ft. lbs. | Small Game |
| 25–41 ft. lbs. | Medium Game (Deer, Antelope) |
| 42–65 ft. lbs. | Large Game (Elk, Black Bear, Boar) |
| 65 ft. lbs. | Big Game (Cape Buffalo, Grizzly) |
Archived capture, 3 June 2011 · Easton's current kinetic energy page
Read the bands carefully, because this is where most republished versions go wrong. Easton's rows are ranges, and the floor of a range is its lower number. We take 25 for deer and 42 for elk. Using a band's ceiling as a minimum is how elk ends up quoted at 65 ft-lb, which is a figure Easton assigned to cape buffalo.
Why small game is 15, and why we say it is ours
Easton's only small-game entry reads "25 ft. lbs. — Small Game", and in context that is a ceiling describing the band small game sits in, not a minimum. So it gives no floor, and nobody else publishes one.
What we can point at is Pope & Young's minimum legal hunting arrow: 300 grains with a 7/8" head. Driven by the lightest bows anyone actually hunts with, that arrow makes roughly 15–19 ft-lb. We take 15 — the bottom of that range — so the floor sits at or below the lightest legal setup rather than above it. The evidence for any specific figure here is thin and we would rather say so than invent precision. Small game is not where energy binds; a sharp broadhead in the right place is.
Why moose is 50 and not 65
Easton charts elk at 42 and cape buffalo at 65, and moose falls between them on mass while sitting nowhere near buffalo on armour. A moose is a thin-hided cervid: no horn boss, no one-to-two-inch shield, no hide plate. Its difficulty is a large dense scapula and the sheer depth of the chest, and it carries the biggest vital zone in North America.
At ~800–1,600 lb it overlaps the top of the elk band and the bottom of the buffalo band, so it belongs above elk. But the armour gap that justifies the jump to 65 is simply not there, so it belongs nearer elk than buffalo. 50 ft-lb sits about a third of the way up the charted 42-to-65 interval — deliberately placed, not a split-the-difference number.
Sanity-checked against rigs that kill moose every season: 500 gr at 270 fps makes 81 ft-lb; a 60 lb rig at 480 gr and 250 fps makes 67; a heavy traditional setup at 650 gr and 195 fps makes 55. All clear it with margin, which is the test a floor has to pass.
The honest limit of the 65 figure
65 ft-lb is Easton's charted floor and the top of the only chart that exists. It should be read alongside the field evidence that cuts against it. Ed Ashby recorded 196 consecutive bone-breaching hits on buffalo, roughly one in five taken with a 40 lb recurve making about 35 ft-lb — well under this floor.
So 65 describes ordinary equipment on the heaviest charted animals. It is not the line between lethal and not lethal. What decides those hunts is structural integrity of the arrow, broadhead mechanical advantage, and shot placement.
We have no published basis for any number above 65 and we decline to invent one. For thick-skinned dangerous game — elephant, hippo, rhino — energy is the wrong axis entirely, and we grade arrow weight against the Ashby Bowhunting Foundation's published chart instead. Holding an elephant to a 65 ft-lb energy test meant an 88 ft-lb, 382-grain arrow read as cleared for it, which is nonsense.
Why we do not grade you on momentum
Momentum is the better predictor of penetration and we show it. We do not grade against it, because there is only one published figure to grade against and it is heavily conditional.
That figure is Ed Ashby's 0.57 lb·sec (Arrow Lethality Part IV), and it applies to a broadhead of 3.0 or greater mechanical advantage, for game up through zebra size. Almost no modern broadhead reaches 3.0 MA. Grading every archer against a threshold whose precondition their equipment does not meet would produce a confident number that means nothing.
Why we apply no penalty for mechanical broadheads
The only peer-reviewed recovery-rate study we are aware of — Pedersen, Berry & Bossart (2014), 1,296 deer, IBEP-certified hunters, 1989–2012 — found mechanicals recovered at 90.9% against fixed blades at 82.0%, p = 0.001, and the result held for compounds alone.
That points the opposite way from the common assumption, so we apply no fixed-versus-mechanical penalty in any grade. By Ashby's own mechanical-advantage formula a 2" two-blade expandable actually out-scores a conventional 1⅓" three-blade fixed head.
How to work out your own number
Kinetic energy in foot-pounds is KE = (mass in grains × velocity in fps²) ÷ 450,240. Momentum in slug-fps is (mass in grains × velocity in fps) ÷ 225,218.
Two cautions. Use your measured arrow weight on a grain scale, not the sum of the component spec sheet — they routinely differ. And use a chronographed speed, not the IBO number on the box, which is measured with a 350-grain arrow at 30" draw and 70 lb and will not be your speed.
You can run this against your own build in The Forge, free.
Common questions
How much kinetic energy do I need for elk?
42 ft-lb, which is the floor of Easton's charted 42–65 band for large game. Most modern compounds clear it comfortably. Treat it as the point where energy stops being your limiting factor, not as a quality score.
How much kinetic energy do I need for deer?
25 ft-lb, the floor of Easton's 25–41 medium-game band. Essentially every modern compound and every competent traditional deer setup clears it with room to spare.
How much kinetic energy for moose?
We use 50 ft-lb. That is our number, not a charted one — Easton never published a moose row. It sits about a third of the way up the 42-to-65 interval because a moose outweighs an elk but is not armoured like a buffalo.
Where did the Easton kinetic energy chart go?
It was removed from eastonarchery.com in January 2012 and has 404'd since April 2012. It is verifiable in five Internet Archive captures from 2011. Any page still presenting it as Easton's current guidance is quoting something retired fourteen years ago.
Is kinetic energy or momentum more important for penetration?
Momentum tracks penetration better. The practical problem is that only one published momentum threshold exists, Ashby's 0.57 lb·sec, and it is conditional on a 3.0+ mechanical-advantage broadhead that almost nothing on the market achieves. So momentum is worth watching and hard to grade honestly.
Do mechanical broadheads reduce penetration enough to matter?
The only peer-reviewed recovery study on the question found the opposite: 90.9% recovery for mechanicals versus 82.0% for fixed across 1,296 deer, p = 0.001. We apply no penalty either way.
Is 60 lb of draw weight enough for elk?
Almost always, yes. A 60 lb bow driving a 480-grain arrow at 250 fps makes roughly 67 ft-lb, well past the 42 ft-lb floor. Draw weight is rarely the binding constraint; arrow weight, tune and placement are.
These floors are what The Forge grades your build against, free. Every figure above is tagged with where it came from — if you think one of our judged numbers is wrong, we would rather hear it than have you quote it uncritically.