Nitrox Essentiels is a compact, field-oriented utility designed for recreational and trainee Nitrox divers who need a fast, reliable way to prepare, verify and explain gas calculations before and during dives. Nitrox Essentiels places core nitrox math — PMU/MOD based on FO2 and PpO2 limits, optimal mix suggestions, refill and dilution calculations, and a multi-profile oxygen plan — into a single, clear interface that works offline and supports both metric and imperial units. The app is written to be used at the dive site: quick to open, easy to read in varied light, and able to save basic diver details so common entries do not need to be repeated.
Core features and how they help
The application performs PMU and MOD calculations to determine safe depth limits from a chosen fraction of oxygen and a maximum partial pressure of oxygen. It can suggest an optimal FO2 for a target depth, calculate how much oxygen to add when topping up a mix from air or pure oxygen, and provide simple air-dilution conversions for quick checks. The O2 Plan component lets you compare an air profile with a nitrox profile, estimate a recommended nitrox mix for initial stops, track cumulative CNS and OTU exposure, and keep a history of past plans so you can review previous mixes and decisions. All calculations are presented with the option to reveal the underlying steps for training or verification.
User experience and controls
The interface is focused on clarity and quick entry rather than complex menus. Numeric fields accept precise FO2, PpO2 and depth values, while simple toggles switch between bar/psi and meters/feet. Interactive controls allow you to adjust a target depth and immediately see resulting safe depth limits or suggested FO2; form fields let you enter cylinder size and current mix to compute refill additions. Light and dark themes improve visibility in bright daylight or low-light conditions, and the layout minimizes typing by saving a diver profile with name and initials for repeated use. Every action is designed to return results quickly, making the app practical when you need a rapid verification on the surface or at the boat.
Training mode and verification tools
Nitrox Essentiels includes a training mode that can optionally display calculation steps, intermediate values and brief explanatory notes so students and instructors can follow the reasoning behind a result. This mode is useful during classroom sessions or self-study because it transforms the tool from a calculator into a step-through learning aid. Practice scenarios are easy to create by changing FO2, target depth or PpO2, allowing users to explore how conservative limits, different mixes and varying depths affect MOD and CNS/OTU accumulation.
Progression, history and customization
Progression in the app is framed around building a personal library of saved dive plans and profiles rather than a game-like leveling system. As you save plans you build a useful history that can be revisited to compare approaches for similar dives and learn from prior decisions. Customization is practical: choose units, set a default PpO2 limit, select your preferred theme and store basic diver details to speed future entries. These settings allow the app to adapt to your typical dives and training preferences without introducing unnecessary complexity.
Accessibility, offline use and reliability
Nitrox Essentiels is designed to work entirely offline so calculations and saved plans are always available even when you have no network access at the dive site. The app emphasizes readability with clear type, contrast options and straightforward labels so users with varied experience levels can navigate it quickly. The numeric inputs include sensible ranges and validation to reduce entry errors, and the history feature provides a lightweight audit trail of prior plans for review.
Safety notes and intended audience
This app is a calculation aid and training companion for divers who have received appropriate instruction. Nitrox Essentiels does not replace formal certification, official dive tables, in-tank gas analysis, organizational procedures or the judgment of a trained diver. It is intended for trained or trainee Nitrox divers as a verification and instructional tool, and should always be used in conjunction with established safety practices and a certified instructor or dive supervisor.
If you are looking for a simple, explainable and portable nitrox calculator that supports both quick field checks and step-by-step learning, Nitrox Essentiels offers a compact solution with clear controls, offline operation and a focus on safety and verification.
