# Dalton: Dive Gas Calculator — Nitrox & trimix calculator > Dive gas calculator with transparent formulas and advanced planning tools. (iPhone/iPad app by Tools for Divers, LLC.) - Source: https://appshunter.io/ios/app/dalton-dive-gas-calculator/id6759679904 (this page in markdown: same URL + `.md`) - Developer: [Tools for Divers, LLC](https://appshunter.io/developer/1880150704) - Category: Utilities, Sports - Price: Free with in-app purchases - Rating: 4.00/5 from 1 App Store ratings - Age rating: 4+ - Requires: iOS 26.0 · 12 MB - Languages: American English, French (France), German (Germany), Italian, Japanese, European Spanish - Released: 2026-03-05 - Data updated: 2026-08-11 - Monetization: free with in-app purchases - User reviews in markdown: https://appshunter.io/ios/app/dalton-dive-gas-calculator/id6759679904/reviews.md ## What is Dalton? Know your gas. Trust your numbers. Dalton is the gas calculator that shows its work. Every result is verified against PADI Nitrox Tables, TDI Trimix Tables, and Shearwater manuals. Every formula is published with step-by-step derivations and source citations. No black boxes. GAS CALCULATIONS - MOD (Maximum Operating Depth): Find the safe depth limit for any gas mix based on your ppO2 tolerance - Equivalent Air Depth: Calculate nitrogen loading equivalents for nitrox decompression planning - Equivalent Narcotic Depth: Determine narcotic effects at depth for trimix planning - Best Mix: Find the optimal oxygen percentage for your target depth - Gas Properties: Calculate density, partial pressures, and breathing resistance at depth DIVE PLANNING - Return Number (Dalton Pro): Gas volume required for safe ascent — rule of thirds, fourths, or custom reserve fractions. The overhead environment gas management tool most divers do on paper or skip entirely - Dive Profile Advisor (Dalton Pro): Plan multi-level dives with gas switches and depth segments - Bottom Time Calculator (Dalton Pro): Determine available bottom time based on gas supply and consumption Dalton Pro tools require a one-time in-app purchase. All gas calculation tools are free. FORMULA REFERENCE Tap any result to see the full formula derivation with source citations. Dalton is the only mobile gas calculator that publishes every formula it uses. Teach the math. Show the math. SHARE YOUR CALCULATIONS Share any result as a URL with a QR code. Recipients with Dalton installed open the calculation directly in the app. Everyone else sees a web preview with the full results. Dalton Pro tool links show a result summary before the in-app purchase prompt -- useful for team briefings where not everyone has the app. Export formula cards as branded images. Send your gas plan to a buddy, post it in the group chat, or print it for the dive briefing whiteboard. One calculation, shared with the entire team in seconds. HOME SCREEN AND LOCK SCREEN WIDGETS - Quick Launch: A 2x2 grid that opens MOD, Best Mix, EAD/END, or Gas Properties with a single tap. No navigating through menus at the fill station - Quick MOD Reference: Pre-computed MOD for your selected gas mix, available on home screen and lock screen in circular, rectangular, and inline formats. Glance at your lock screen and see your MOD without opening the app - Both widgets are free - All values are pre-computed inside Dalton. No calculation logic runs in the widget extension SAFETY-FIRST DESIGN - Three-tier safety warnings tied to recognized physiological thresholds - Gas-density guidance from Anthony and Mitchell research: preferred below 5.2 g/L, caution from 5.2 to below 6.2 g/L, danger at 6.2 g/L and above - Configurable safety limits with ppO2 range from 1.2 to 1.6 bar - Standard gas mix presets: Air, EAN32, EAN36, and common trimix blends - Full gas range: air, nitrox, and trimix including hypoxic blends to 300m - All calculations work offline; anonymous crash and release-health diagnostics may be sent when online - No subscriptions, no ads, no account creation Every calculation is verified. Every result is reliable. A Tools for Divers, LLC product ## Key features - MOD calculation - Equivalent Air Depth (EAD) - Equivalent Narcotic Depth (END) - Best Mix calculation - Gas Properties at depth - Return Number calculation (Pro) - Dive Profile Advisor (Pro) - Bottom Time Calculator (Pro) ## Pricing and in-app purchases Base price: Free. **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | Dalton Pro | $14.99 | one-time | ## Frequently asked questions about Dalton ### What is Dalton? Dalton is a dive gas calculator that provides transparent calculations for parameters like MOD, EAD, and END. It shows step-by-step derivations for all its formulas, verified against industry standards. ### Is Dalton free to use? Yes, all core gas calculation tools in Dalton are free to use. Advanced dive planning features like Return Number, Dive Profile Advisor, and Bottom Time Calculator require a one-time in-app purchase. ### What dive gases can Dalton calculate? Dalton supports a full gas range including air, nitrox, and trimix, even hypoxic blends. It can calculate parameters for depths up to 300m. ### Does Dalton have ads? No, Dalton does not contain advertisements. The app is designed to be ad-free for a focused user experience. ### Can I share my calculations from Dalton? Yes, you can share any result as a URL with a QR code. Recipients can open the calculation directly in the app or view a web preview. ### What devices does Dalton support? Dalton is available for iPhone and iPad devices, offering a mobile solution for dive planning. ### How often is Dalton updated? The latest version of Dalton is 1.2.0, last updated on May 29, 2026. Updates typically include new features, bug fixes, and performance improvements. ### Does Dalton work offline? Yes, Dalton is designed with an offline-first approach, meaning it does not require an internet connection to perform calculations. ## Version history (last 5 releases) ### 1.2.1 — 2026-08-11 Dalton 1.2.1 is a small safety and reliability update. • Corrected gas-density calculations to use component-density planning guidance: preferred below 5.2 g/L, caution from 5.2 to below 6.2 g/L, and danger at 6.2 g/L and above. • Warning cues now use safety amber instead of lime green. • Anonymous release-health diagnostics and exact crash-symbol verification improve our ability to fix crashes and hangs without behavioral tracking. ### 1.2.0 — 2026-05-29 Dalton 1.2 brings glanceable safety data to your Home and Lock Screens, hands-free calculations, and stronger safety checks on shared links. • New Favorite Gas Mix Reference widget — pin a gas mix and reference depth, glance MOD, ppO₂, and gas density without opening the app. Three families for Home Screen and Lock Screen. Hard-fails to a safety placeholder when reference depth exceeds the mix's MOD. • Ask Dalton with Siri Shortcuts — MOD, EAD, END, Best Mix, and Gas Density now work hands-free. Trimix-only calculations stay gated behind Technical Diver mode. • Shared calculation links are validated against Dalton's safe-range rules before any tool state is populated. Links carrying unsafe values (ppO₂ > 1.6, O₂ ≥ 100%, depth > 200 m) are refused with a clear alert naming the offending field. ### 1.1.2 — 2026-04-17 Fixed a layout issue where calculator screens could clip or overlap content when a safety warning banner was visible. Affects Best Mix, Operating Limits, Gas Properties, Equivalent Depths, Dive Profile Advisor, and Bottom Time. ### 1.1.1 — 2026-04-07 - Share any calculation via link: generates a URL with QR code that opens in Dalton or falls back to a web preview - Shareable formula cards with branded image export for dive team briefings - Quick Launch home screen widget: 2x2 grid to open MOD, Best Mix, EAD/END, or Gas Properties with a tap - Quick MOD Reference widget: shows pre-computed MOD for a selected gas mix on home screen and lock screen - Lock screen widget support: circular (MOD value), rectangular (gas name + MOD), and inline formats - Deep link preview mode for Pro tools (shows calculation result before prompting unlock) - Share actions consolidated into a single toolbar menu (link, QR code, image card, text) - Replaced hardcoded styling with DFUI semantic theme tokens throughout the app - Improved readability of tool explainer cards - QR code rendering reliability on first generation - Share sheet preview showing raw text instead of card image ### 1.1 — 2026-03-24 Your calculations, anywhere. Dalton 1.1 adds link sharing, home screen widgets, and a cleaner interface -- turning a personal gas calculator into a team coordination tool. LINK SHARING Share any calculation as a URL. Dalton generates a shareable link and QR code for every result. Recipients with Dalton installed open the calculation directly in the app. Everyone else sees a web preview with full results. Pro tool links show the result summary before any unlock prompt -- useful for team briefings where not everyone has the app. Shareable formula cards export as branded images. Send your gas plan to a buddy, post it in the group chat, or print it for the dive briefing whiteboard. One calculation, shared with the entire team in seconds. WIDGETS Two home screen widgets ship with this update, both free: - Quick Launch is a 2x2 grid that opens MOD, Best Mix, EAD/END, or Gas Properties with a single tap. No navigating through menus at the fill station. - Quick MOD Reference displays the pre-computed MOD for a gas mix you select. Available as a home screen widget and as a lock screen widget in circular, rectangular, and inline formats. Glance at your lock screen and see your MOD without opening the app. POLISH - Share actions consolidated into a single toolbar menu - Improved tool explainer readability - Updated theme styling throughout Dalton is a verification tool, not a dive computer. Always confirm your gas plan independently before diving. ## Apps similar to Dalton | App | Rating | Price | Category | | --- | --- | --- | --- | | [Cylindex -Cylinder Inspections](https://appshunter.io/ios/app/cylindex-cylinder-inspections/id6741502559) | — | Free | Utilities | | [Barefoot Blender](https://appshunter.io/ios/app/barefoot-blender/id6773279505) | — | Free | Utilities | | [Dive Exporter](https://appshunter.io/ios/app/dive-exporter/id6758713452) | — | Free | Utilities | | [Rigging Tools](https://appshunter.io/ios/app/rigging-tools/id6755364737) | — | Free | Utilities | | [Wristy](https://appshunter.io/ios/app/wristy/id6443986821) | 1.0 (1) | $0.99 | Utilities | | [Twixt Time](https://appshunter.io/ios/app/twixt-time/id541686012) | 3.8 (13) | $9.99 | Utilities | ## More apps by Tools for Divers, LLC - [Slate: Dive Logbook](https://appshunter.io/ios/app/slate-dive-logbook/id6759878835) All apps by Tools for Divers, LLC: https://appshunter.io/developer/1880150704 ## Related topics [dalton](https://appshunter.io/ios/topics/dalton) --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-11.*