It’s the real engine
Not a re-implementation. The same Rust solver the app uses, compiled to WebAssembly — so the web answer and the app answer match to the millimetre.
Free web calculator
Airgun ballistics calculator, in your browser.
The real PelletArc engine — the same Rust core as the app — compiled to WebAssembly and running entirely on your device. Change anything; the holdover updates live. Nothing is uploaded.
Holdover
— mil
Wind
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Speed
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Energy
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| Range m | Drop cm | HOLD mil | Vel m/s |
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The free web solver stops at 35 m, the same as the app’s free tier. Get the app for unlimited range.
Runs the actual PelletArc Rust core in your browser via WebAssembly — parity-tested against published JBM tables, capped at 35 m like the free tier. The app adds unlimited range, the reticle view, BC truing, saved profiles and an offline holdover-card PDF.
Good to know
Honest about what this is
Box BC is a starting point
Catalogue BCs vary by source and velocity. For a real-world hold, true the BC from your own observed drops in the app.
The field needs the app
Offline use, the on-scope reticle view, the 1,680-pellet catalogue and PDF cards live in iOS & Android.
Is this the real PelletArc engine?
Yes — out to 35 metres. The same Rust ballistics core that ships in the app is compiled to WebAssembly and runs entirely in your browser, nothing is sent to a server. The web solver matches the app’s free tier and stops at 35 m; the app adds unlimited range, the reticle view, BC truing, saved profiles, holdover-card PDF export and full offline use in the field.
Which drag models can I use?
All nine: GA and GA2 for domed diabolos, WC0 for wadcutters, SLG0/SLG1 for slugs and GS for round balls, plus G1/G7 for rifle projectiles and RA4 for .22LR rimfire.
What if I don’t know my BC?
Start with a catalogue estimate, then true it: in the app you log two or three observed drops and PelletArc fits a velocity-dependent BC to your barrel and pellet. See the guide on BC truing.
Get PelletArc
Take the solver to the field.
iOS & Android · one-time purchase · works fully offline.
Launching on iOS & Android. Pay once — no subscription.