Energy Guide · FPE
How much FPE do you need? Airgun energy chart by quarry
By James · Published · Updated · Editorial policy
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The quarry guidance below combines published recommendations (linked in Sources) with the energy floor I hunt by. The FPE-by-speed tables are computed with the same formula as my FPE calculator (grains × fps² ÷ 450,436, the AAFTA divisor), not measured. Your chronograph has the final say. Full methodology & editorial policy →
Airgun energy chart by quarry
| Quarry | Published guideline (muzzle) | My floor at the animal | Caliber I'd use | Shot |
|---|---|---|---|---|
| Rats, mice, sparrows, starlings | 6–12 FPE | 6+ FPE | .177 or .22 | Head |
| Tree & ground squirrels | 12–20 FPE | 9–12+ FPE | .22 | Head |
| Cottontail rabbits | 12–20 FPE | 9–12+ FPE | .22 | Head |
| Jackrabbits & hares | 12–20 FPE | 12+ FPE (20+ at the muzzle recommended) | .22 or .25 | Head, or heart-lung up close |
| Pigeons & Eurasian collared doves | 12–20 FPE | 12+ FPE | .22 | Head or upper chest |
| Raccoons, groundhogs, opossums | 20–40 FPE | 25+ FPE | .25 or larger | Head |
| Coyotes, hogs, turkeys | 40–100 FPE | Big-bore territory | .30 and up | Check legality first |
Legal minimums can be much higher than these bands. Texas requires a .30 caliber PCP firing 150 grains at 800 fps, or at least 215 ft-lb, for deer and for turkey outside the East Zone. West Virginia allows turkey with a .22 or larger air rifle. Check your own state in the air rifle hunting laws guide, and see the FPE for hunting guide for energy at the target.
The guideline column follows Umarex's published FPE bands, which are muzzle-energy ranges. My column is what I want arriving at the animal, which is stricter because energy drops with distance. Mourning doves aren't on this chart for a reason: they're federally protected migratory birds and air rifles aren't a legal method for them.
FPE by pellet weight and speed
Look up your projectile weight and its chronographed speed. The number where they meet is your muzzle energy. Energy depends only on weight and speed. Caliber changes how the energy is delivered, not how much there is.
| Caliber | Weight | 600 fps | 700 fps | 800 fps | 900 fps | 1000 fps |
|---|---|---|---|---|---|---|
| .177 | 8.44 gr | 6.7 | 9.2 | 12.0 | 15.2 | 18.7 |
| .177 | 10.34 gr | 8.3 | 11.2 | 14.7 | 18.6 | 23.0 |
| .22 | 14.35 gr | 11.5 | 15.6 | 20.4 | 25.8 | 31.9 |
| .22 | 15.89 gr | 12.7 | 17.3 | 22.6 | 28.6 | 35.3 |
| .22 | 18.13 gr | 14.5 | 19.7 | 25.8 | 32.6 | 40.2 |
| .22 | 25.39 gr | 20.3 | 27.6 | 36.1 | 45.7 | 56.4 |
| .25 | 25.39 gr | 20.3 | 27.6 | 36.1 | 45.7 | 56.4 |
| .25 | 33.95 gr | 27.1 | 36.9 | 48.2 | 61.1 | 75.4 |
Computed: FPE = grains × fps² ÷ 450,436. Weights are common real-world options (for example 8.44 gr .177, 15.89 and 18.13 gr .22, 33.95 gr .25).
How fast does a .22 need to go for 12 FPE?
This is the speed that has to arrive at the rabbit, not leave the muzzle, to deliver the floor energy:
| .22 projectile weight | Speed needed for 12 FPE | Speed needed for 20 FPE |
|---|---|---|
| 14.35 gr | 614 fps | 792 fps |
| 15.89 gr | 583 fps | 753 fps |
| 18.13 gr | 546 fps | 705 fps |
| 25.39 gr | 461 fps | 596 fps |
Heavier pellets need less speed for the same energy. But they drop faster, which makes holdover discipline more important past 30 yards.
Muzzle energy vs energy at the animal
Every number printed on a box, and every number in the tables above, is muzzle energy. Pellets start shedding speed the moment they leave the barrel. How fast depends on the projectile's shape and ballistic coefficient. Slugs and heavy domed pellets hold speed better than light, flat-nosed ones. By 40–50 yards, a light pellet can have lost a meaningful share of its energy.
Three ways to stay honest:
- Chronograph at the muzzle, then run your ballistic coefficient through a ballistics app to estimate speed at 40–50 yards.
- Or chronograph at distance. Set the chrono up at 30–40 yards (safely!) and measure what actually arrives.
- Or build in cushion. This is why I say ~15+ FPE at the muzzle for a 12 FPE floor at typical rabbit ranges.
Why placement beats power
A .22 pellet in a rabbit's brain at 10 FPE kills cleanly. The same pellet in the gut at 40 FPE doesn't. Jim Chapman makes the same point in Afield on Airguns: accuracy first, power second. Extra energy buys you range, meaning the ability to still have enough energy at 60+ yards. It doesn't make normal shots deader. That's the core argument of my rabbit rifle tiers.
Run your own load in the FPE calculator →
Caliber and energy toolkit
- Air rifle FPE for hunting: the complete guide, from measuring FPE to energy at the target.
- FPE and ballistics calculators compared: which tool to use for energy, legal limits and holdover.
- Best airgun caliber for small game: .22 vs .25 with the energy math.
- Airgun FPE calculator: your own pellet weight and chronographed speed.
- .22 vs .25 for rabbit hunting: energy, wind, shot count and cost.
FAQ
How many FPE does it take to kill a rabbit?
About 9–12+ FPE delivered to the rabbit's head. I use 12 FPE at the animal as my floor, which usually means a rifle making 15+ FPE at the muzzle so there's cushion left at field distances.
How many FPE do you need for squirrels?
The same 9–12+ FPE at the animal as rabbits, with a head shot. Squirrels are small but tough, and a body hit often means a squirrel lost in a tree or a burrow.
Is 12 FPE enough for hunting?
For rabbits, squirrels, and pest birds with head shots at sensible ranges, yes. It's the UK's legal limit for air rifles without a firearms certificate, and British hunters take huge numbers of rabbits at that power. It is not enough for raccoon-sized animals or coyotes.
How do you calculate airgun FPE?
FPE = projectile weight in grains × velocity in fps² ÷ 450,436. Example: an 18.13 gr pellet at 900 fps = 18.13 × 810,000 ÷ 450,436 = 32.6 FPE. Use your chronographed velocity, not the box number.
What FPE is a .22 air rifle?
It depends on the rifle and the pellet. Entry spring guns and small PCPs sit around 12–20 FPE, typical hunting PCPs 25–45 FPE, and high-power PCPs shooting heavy slugs go well past that. Chronograph your own rifle to know.
Is more FPE always better for hunting?
No. Past the energy that reliably kills your quarry, extra power buys range, not deader animals. It also costs you noise, air, shot count, and often accuracy. Pick the energy your quarry and distance need, then work on accuracy.
