What is Atlas Ballistics?

Atlas Ballistics manages 2 data types including support articles. Helps you organize, track, and share your work in 1 place for teams and solo users.

How is bullet energy calculated?

Kinetic energy in foot-pounds is (bullet weight in grains × velocity in fps²) ÷ 450,240. The hard part is the velocity: Atlas runs a full Runge-Kutta trajectory integration with G1/G7 drag curves and your atmospherics to work out how much speed the bullet has actually retained at your target distance.

How much energy do I need for an ethical kill?

Common guidelines are roughly 1,000 ft·lbs for elk, 1,500+ for moose and large bear, and about 1,000 ft·lbs for deer, though shot placement and bullet construction matter more than the raw number. Many states also publish minimums. Always check your local regulations and your bullet maker's recommended impact-velocity window.

Should I use my G1 or G7 ballistic coefficient?

Use G7 for long, boat-tailed match and hunting bullets and G1 for shorter, flat-based bullets. Whichever you pick, enter the matching BC value from the box — a G1 number entered as G7 will overstate retained velocity badly.

Does temperature and altitude change bullet energy?

Yes. Thinner air at altitude or in hot weather means less drag, so the bullet holds velocity longer and hits with more energy. Enter your station temperature and elevation to see the difference — it can be well over 100 ft·lbs at 1,000 yards.

Is this the same solver as the Atlas Ballistics app?

It is the same trajectory engine, run on our servers and verified against the app's reference test suite, so the numbers match exactly. The app adds wind, spin drift, Coriolis, aerodynamic jump, truing from your real shots, and offline range cards.

Features

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Free Ballistic Tool

Bullet Energy Calculator

Enter your load and get retained kinetic energy, velocity, drop and elevation hold at any distance — solved with the same G1/G7 trajectory engine that powers the Atlas Ballistics app.

Load

Muzzle velocity

fps

Bullet weight

Ballistic coefficient

Drag modelTarget range

Rifle

Zero range

Sight height

Conditions

Temperature

°F

Altitude

Results update as you type. Solved server-side with full drag integration — not a simplified approximation.

Retained energy at 500 yd

1,382

ft·lbs

Velocity

1,885 fps

Flight time

0.67 s

Drop

56.4 in

Downrange table

Velocity, energy and elevation hold at every 100 yards.

Range	Velocity	Energy	Elevation
100 yd	2,524 fps	2,475	—
200 yd	2,354 fps	2,154	1.8 MOA ↑
300 yd	2,191 fps	1,866	4.3 MOA ↑
400 yd	2,035 fps	1,610	7.4 MOA ↑
500 yd	1,885 fps	1,382	10.8 MOA ↑
600 yd	1,743 fps	1,181	14.6 MOA ↑
800 yd	1,485 fps	857	23.8 MOA ↑
1,000 yd	1,270 fps	627	35.3 MOA ↑

What bullet energy actually tells you

Kinetic energy is the standard way shooters and hunters compare how much work a bullet can still do at distance. It falls off fast: energy scales with the square of velocity, so a bullet that has lost a third of its speed arrives with less than half of its muzzle energy.

That's why muzzle energy alone is a poor way to judge a load. A high-BC bullet leaving slower can easily out-hit a faster, draggier bullet at 500 yards. Enter both loads above and compare the numbers at your real target distance rather than at the muzzle.

Energy is one input to a terminal-performance decision, not the whole answer. Bullet construction and impact velocity determine whether a projectile expands the way it was designed to, so check your bullet maker's minimum impact velocity alongside the energy figure here.

Get the full solver in your pocket

Atlas Ballistics runs this same engine on your phone — with wind, spin drift, Coriolis, aerodynamic jump, truing from real shots, saved rifle and ammo profiles, and range cards that work offline.

Download on the App Store

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