Gadsden Ballistic Calculator

Long-range trajectory with a DOPE card you can read in the field. Free to 1,000 yd, G1/G7, Coriolis, spin drift, live weather. $9.99 unlocks 3,000 yd. No subscription.

Gadsden Ballistic Calculator is a precision long-range trajectory solver for competitive shooters, long-range hunters, and military and LE precision teams. Enter your rifle, your load and the conditions, and get a firing solution and a DOPE card you can actually read in the field.

A SOLVER THAT PUBLISHES ITS NUMBERS 3-DOF point-mass trajectory, 4th-order Runge-Kutta integration at a 0.5 ms time step. We check it against JBM Ballistics' published outputs before every release: across our published golden-test suite the maximum velocity error is 0.38% and the average is 0.21%. That verification is ours, run in our own test suite — we publish the numbers so you can judge them. Every physics constant in the engine cites its source.

WHAT IT CORRECTS FOR

• G1 and G7 drag models
• Full atmosphere: temperature, pressure, humidity, altitude, density altitude
• Spin drift (Miller stability factor, Litz drift formula)
• Coriolis, including the vertical Eotvos effect, in both hemispheres
• Aerodynamic jump
• Uphill and downhill angle compensation
• Powder-temperature muzzle-velocity correction
• Moving-target leads
• Transonic and subsonic markers on the trajectory chart
• Muzzle-velocity truing from your observed drop

BUILT-IN CATALOGUES 253 cartridges. 481 factory loads from 28 manufacturers across 115 calibers. 236 scopes and 229 mounts. Add your own rifles and handloads, or import a load you already have.

IN THE FIELD

• Range card and DOPE card, MOA or MRAD, imperial or metric throughout
• Full-screen Field HUD with numbers big enough to read behind the rifle
• Reticle holdover drawn to true scale
• Home-screen widgets: last solve, DOPE card, current setup
• All 12 wind clock positions, compass-aware
• Live weather for your location, or enter atmospherics by hand
• A Daylight theme built to stay readable in direct sun

FREE, WITH NO CLOCK ON IT 3 rifle profiles, 5 ammo loads, 10 catalogue imports, solutions out to 1,000 yards, both drag models, every correction listed above, live weather, muzzle-velocity truing, and the Dark and Daylight themes. No ads. No trial period. No account.

PRO — $9.99, ONCE

• Range out to 3,000 yards
• Unlimited rifle profiles, ammo loads and catalogue imports
• Ballistic-coefficient truing
• PDF and CSV export for printed cards
• 25 and 50 yard step sizes
• All 5 themes
• Kestrel 5000-series weather meter over Bluetooth (beta)

One payment, not a subscription. The price shown in the App Store is the price.

PRIVACY No account, no sign-in, no analytics, no tracking, no ad SDKs. We never receive your data — backups go only to your own iCloud account. The solver runs entirely on your device, so it works with no signal; the only things that ever leave your device are a weather lookup, if you use live weather, and anything you type into the feedback form. A Kestrel connection (beta) is a direct Bluetooth link to your own meter and sends nothing anywhere.

Shooting is your responsibility. Confirm every solution on paper at the range before you rely on it in the field.