Ballistic Calculator 2

A free, open-source ballistic calculator for Windows, Linux and macOS, built on Avalonia UI.

This is the successor to the WinForms Ballistic Calculator .NET, rewritten from the ground up to be genuinely cross-platform rather than Windows-with-Wine. The trajectory mathematics comes from the BallisticCalculator library.

Drop, windage, clicks, energy and time of flight out to 1,000 yd — .223 69 gr Sierra, 300 yd zero. Click any image to open it full size.

📖 User guide — installation, what the model includes, and where to learn the ballistics behind the inputs.

Goals

Accuracy comparable to commercial and 4DOF solvers. The engine is a 3DOF (point-mass) integration with the correction terms that matter in the field — spin drift, crosswind aerodynamic jump and the Coriolis effect — and it accepts measured drag curves, which is where real accuracy comes from. A point-mass solver running the projectile's own Cd curve tracks a 4DOF solver closely; what a 4DOF model adds is the projectile's angular motion, not a better drag model. So rather than approximating that, this calculator lets you supply or build the actual curve.

Truly cross-platform. One codebase, native builds for Windows, Linux and macOS, no emulation layer. Each release ships both.

Android next. The shared calculation and domain layers (Common/) carry no desktop UI dependencies, so a touch-first mobile app can be built on them rather than around them. That work has not started yet.

What it does

Trajectory

• 3DOF point-mass integration, with spin drift, crosswind aerodynamic jump (Litz / Applied Ballistics) and the Coriolis effect (barrel azimuth + shooter latitude)
• Uphill and downhill shots, scope cant, multiple wind zones along the flight path
• Zeroing with a different cartridge, atmosphere or wind than the shot itself — zero with supersonic, shoot subsonic
• Results as a table, a chart, and a sight picture through your own reticle; several trajectories can be compared on one chart, and any table can be exported to CSV

Spin drift and aerodynamic jump need the rifling twist plus the bullet's diameter and length; Coriolis needs the barrel azimuth and your latitude. Leave them out and those terms are simply absent.

Drag models

• All the standard curves — G1, G2, G5, G6, G7, G8, GI, GS, RA4
• Custom drag tables (.drg) — the projectile's own measured Cd curve
• Approximate a drag table you do not have, two ways:
  • from a multi-BC curve (BC quoted at several Mach numbers, as published on many data sheets)
  • from measured downrange velocities (radar or chronograph data)
• Convert a ballistic coefficient between standard tables — the everyday G1 ↔ G7 question, at a reference velocity you choose, with the accuracy caveat stated rather than hidden

Analysis