NeuraTiM DecoLab
One dive. Six models. See the difference.
Explore how decompression models change a dive plan. Compare six models, build multilevel schedules with gas switches and consumption estimates, or take control of an interactive simulation. Planning runs on your device, without an account or automatic upload of your dive data.
Deco Plan — a 40 m air dive, with ascent starting 25 min after the dive begins. Bühlmann ZH-L16C with GF 30/85. Example output from the app.
Six models, one dive
Choose the model with the differences in view.
Decompression time depends on the model and its settings. DecoLab calculates the same dive with six models and puts their schedules side by side, so you can see where they differ. A shorter schedule is not, by itself, a safer or better one.
Bühlmann ZH-L16C + GF
Bühlmann ZH-L16C with adjustable low and high gradient factors. Compare how your conservatism settings affect the calculated ascent.
Bühlmann ZH-L16B + GF
An alternative Bühlmann parameter set, included so you can compare its results with ZH-L16C under the same dive conditions.
RGBM
Based on published Reduced Gradient Bubble Model equations by Bruce Wienke. An educational approximation, not a match to a particular manufacturer's dive computer.
US Navy Standard Air
The US Navy Standard Air Decompression Table, Revision 6, applied to one depth and one duration. This option does not support gas switching or multilevel profiles.
VPM-B
The Varying Permeability Model, with the VPM-B extension. In the example below, it produces a deeper first stop and a longer total runtime than the Bühlmann options.
VPM-B/GFS
VPM-B with a gradient-factor surfacing criterion for the final ascent. Compare it with VPM-B to see whether that criterion changes the result for your chosen dive.
40 m · ascent starts at 25 min runtime · air · salt water · GF 30/85 where applicable · last stop 6 m
| Algorithm | First stop | TTS | Total runtime | CNS | OTU |
|---|---|---|---|---|---|
| Bühlmann ZH-L16C + Gradient Factors | 15 m | 43:15 | 68:15 | 10 % | 28 |
| Bühlmann ZH-L16B + Gradient Factors | 15 m | 36:41 | 61:41 | 10 % | 28 |
| RGBM (Reduced Gradient Bubble Model) | 9 m | 37:08 | 62:08 | 10 % | 28 |
| US Navy Standard Air Decompression Table | 6 m | 30:40 | 55:40 | 10 % | 28 |
| VPM-B (Varying Permeability Model, Boosted) | 18 m | 48:13 | 73:13 | 10 % | 28 |
| VPM-B/GFS (Gradient Factor Surfacing) | 18 m | 48:13 | 73:13 | 10 % | 28 |
In this example, first-stop depths differ by 12 m and total runtimes by 17 min 33 s. These are differences between model outputs, not a ranking of dive safety.
Your diving mode. Your level of detail.
Two switches. Four ways to use DecoLab.
Choose Recreational or Technical to set which screens are available, then UI Minimal or UI Full to set how many fields appear. In every combination, hidden settings use global defaults, not previously saved per-screen overrides.
Recreational
The default mode. Calculations use the model and conservatism set in Settings, with fewer controls to manage.
- Six screens: Deco Plan, NDL, NDL Table, Calculation, Gases & Tanks, Settings
- One default model, chosen in Settings
- No per-screen model selection or conservatism overrides
- Full schedules, dive profiles, gas consumption and printable plans
- Backup and restore, with optional encryption
For recreational divers, those moving into technical diving, and anyone who prefers one selected model to a comparison.
Technical
Everything in Recreational, plus four advanced screens. UI Full also exposes model selection and settings that apply only to the current calculation.
- All ten screens, including Compare Algorithms, Recommend Gas, Gas blending and Simulation
- Model selection on supported calculation screens with UI Full
- Per-screen overrides with UI Full, including gradient factors, ascent rates and ppO₂ limits
- Compare six models on one dive and inspect each result in full
- Interactive simulation at 1× to 30× real time
For technical and trimix divers, instructors, and anyone exploring how decompression models behave.
Choose how much detail to show
The second switch changes how many fields you see, not which screens are available. UI Minimal hides fields that repeat global settings and uses the values from Settings. Hidden per-screen overrides are not used.
UI Minimal
The default layout. Enter depth and oxygen percentage on the NDL screen; cylinder volume and fill-pressure fields stay hidden in plan cards. Water type, model and other hidden options use the applicable global settings.
UI Full
Show additional fields, including water type and cylinder details. In Technical mode, you can also choose a model and override supported settings for an individual calculation.
Both switches sit at the bottom of the navigation. Recreational ↔ Technical changes the available screens; UI Minimal ↔ UI Full changes the visible fields. Your choices are remembered without deleting your plans or other data.
The ten screens
From a quick answer to a full instrument panel
Each screen answers a different planning question. Choose one to explore its layout and tools.
What does the full dive schedule look like?
Set depth levels, gases, model, conservatism, water type and last stop. Calculate a schedule covering descent, time at depth, gas switches, ascent and decompression stops.
- Multiple depth levels, with a specified gas or automatic gas selection at each level
- Summary values, a profile with the decompression ceiling, a schedule and consumption per cylinder
- “How this plan was calculated” shows the settings behind the result
- Print, share, save or export the plan, or open it in the simulation
Two switches, below the navigation
Technical mode shows all ten screens. Recreational hides Compare Algorithms, Recommend Gas, Gas blending and Simulation. UI Minimal and UI Full control field visibility. Whenever an option is hidden, its global setting is used instead of a stored per-screen override.
Styles
Eight styles. The same plan.
Choose the look you like. A style changes every screen — surfaces, titles, fields, buttons and result tiles — but never the calculation. Each phone below shows the same computed plan in one of the app's eight styles.
Bento cockpitDefault
A modern dashboard: clean tiles with value bars, mint accents and compact field captions.
Dive computer
Instrument panels with thin borders, square controls and compact titles.
Lab blueprint
An engineering drawing: outlines, monospace type and ruled titles.
Colour-coded zones
A colour for each section: round icon badges, leading strips and large rounded cards.
Calm editorial
No card fills: open sections, large light titles and a single accent colour.
Nautical chart
A printed chart: paper, depth contours, double rules, serif type and signal orange.
Bioluminescence
Translucent glass panels with glowing edges over a water gradient.
Expressive tonal
Tonal pastel surfaces, round icon badges and pill-shaped controls.
Shown in the light theme. Every style also has a dark variant, and you can switch at any time in Settings → Style.
Gas blending
Two ways to work out your fill
Plan partial-pressure blending or transfers between cylinders on one screen. See the gas additions, target gauge readings and remaining source pressures. These calculations do not replace gas-blending training, suitable equipment or analysis of the finished mix.
Partial-pressure blending
Enter the starting mix and pressure, then the target mix and fill pressure. The app calculates any gas to release first and the helium, oxygen and air to add. For example, its model brings 150 bar of 10/70 down to 128.6 bar before blending 18/45 at 200 bar: the starting mix contains more helium than the target fill needs.
Cylinder-to-cylinder transfer
Gas transfers from a higher-pressure source until the pressures equalise or you stop the transfer. The incoming gas has the source's composition; the final mix depends on how much is transferred. Add source banks, specify whether an air compressor is available, and set the working-pressure limit to calculate the transfer order and stopping pressures.
A plan for an achievable fill
Three gases, one calculation
Both methods support nitrox and trimix, accounting for oxygen, nitrogen and helium. For example, sources containing 10/70, air and oxygen can be combined to make 18/45; the calculation works out each source's contribution.
See the alternatives
When the requested fill is not achievable, the app explains the constraint and offers alternatives where available — for example, EAN29 at 140 bar or the requested EAN28 at 131.8 bar. Each alternative includes its own filling steps.
See what needs to change
The app also shows what would make the target possible: for example, a source at 186.8 bar instead of 150 bar, a source mix between EAN38.8 and EAN45.5, or an available air compressor.
The blending solver is tested against an independent simulator across hundreds of nitrox, trimix and multi-bank cases. These checks look for both unworkable plans and achievable fills the solver might miss, within the model's assumptions.
Calculation details and printable plans
“23 minutes of deco” needs some context.
A schedule depends on its assumptions: gradient factors, water type, gases and residual loading from previous dives. DecoLab keeps those settings alongside the result and includes them in a printable plan, so the numbers remain understandable outside the app.
- Model
- Bühlmann ZH-L16C + Gradient Factors
- Gradient factors
- 30 / 85
- Water
- Salt water · 1025 kg/m³
- Gases
- Air
- Previous dives
- None — no residual loading from previous dives assumed
- ppO₂ limits (bar)
- 1.40 at depth · 1.60 during decompression
- Rates (m/min)
- ↓ 18 · ↑ 9 · between stops 3 · final ascent 3
- Stops
- Every 3 m; last stop at 6 m
- Generated
- 2026-08-04 13:06 UTC+02:00
- Produced by
- NeuraTiM DecoLab 1.1.0
Decompression schedule
| 2:13 min | Descend · 0 → 40 m · 2:13 min · Air |
| 25:00 min | At depth · 40 m · 22:47 min · Air |
| 28:27 min | Ascend · 40 → 15 m · 3:27 min · Air |
| 28:47 min | Deco stop · 15 m · 0:20 min · Air |
| 66:15 min | Deco stop · 6 m · 30:19 min · Air |
DecoLab is a planning and teaching tool, not a dive computer. Cross-check this plan with a dedicated device, follow your training and remember that no decompression model eliminates risk.
Page 1 of a printable plan for the same 40 m example dive.
The simulation cockpit
Take the controls, second by second
On a wide screen, the simulation becomes a three-column instrument panel: profile and controls, live indicators, and tissue loading and stops. Cylinders and dive history fit alongside them, so you can read the ceiling, projections and remaining gas together.
What you can follow
- Depth, runtime and maximum depthCurrent depth, elapsed dive time and maximum depth reached.
- Decompression ceiling and surface GFThe model's shallowest permitted depth and the estimated gradient factor at the surface if you surfaced now.
- Eight time-to-surface estimatesEight time-to-surface estimates: using all planned gases or only the current gas, for an ascent now or after another 1, 5 or 10 minutes at depth.
- Gas time remainingEstimated breathing time remaining at the current depth and consumption rate, shown for each cylinder.
- ppO₂, CNS, OTU, density and ENDOxygen partial pressure, CNS oxygen-exposure percentage, oxygen tolerance units (OTU), gas density and equivalent narcotic depth (END). Gas density helps assess breathing demands; it is not a direct measurement of breathing effort.
- Tissue loadingSixteen modelled tissue compartments on a body diagram, with a consistent colour scale and the leading compartment highlighted. The diagram illustrates the model, not actual anatomical tissue measurements.
Example output from the app at 40 m on air, 15:02 into the dive, after the no-decompression limit has been exceeded. These are model calculations, not measurements of a diver's body or a prediction of individual medical risk.
Simulation controls
Control depth and time
Change depth in ±1 m or ±5 m steps, choose a target depth, ascend to the next stop or return to the surface. Advance time by 30 seconds or by 1, 5 or 10 minutes, with the simulation running or paused.
Your dive, at your pace
Run at 1×, 2×, 5×, 10× or 30× real time, or load a calculated plan and watch it play back. At 30×, one real second represents 30 simulated seconds.
See what losing a cylinder changes
Switch gas instantly or over the configured switch time. Exclude a cylinder to simulate losing access to it, and see the time to surface and stop schedule recalculate for the remaining gases.
Arrange the panel your way
Hide individual indicators and restore them using the controls below the panel. Your layout is saved, so the values you care about stay in view.
Your data
Your backups. Checked before restore.
Your settings and plans are stored on your device. Export a backup to keep a separate copy, with optional passphrase protection. Imported files are checked before any existing data is replaced; invalid files are rejected with an explanation.
A readable JSON backup
Settings, cylinders, cylinder configurations and saved plans fit into one readable JSON file. Keep a copy you can inspect without DecoLab.
Optional encryption
Protect the same data with a passphrase. Encryption uses AES-256-GCM and a key derived with PBKDF2-SHA256 at 210,000 iterations, all on your device. Keep the passphrase safe: we cannot recover it or open the encrypted backup without it.
Tampering is detected
The encrypted backup's header is authenticated along with its contents. Changes to protected data — such as the iteration count or salt — cause validation to fail rather than silently restoring altered content.
Check first, then restore
Before you confirm a restore, the app checks the file's structure, size limits and individual fields. If validation fails, it identifies the problem and leaves your existing data unchanged.
Consistent input limits
The same documented value ranges apply to form entries, stored records and imported files. Out-of-range values are rejected, not silently adjusted: an ascent rate of 400 m/min is not quietly changed to 30 m/min.
The right file for the right import
Full backups and individual plan files declare their file type. The app rejects a file supplied to the wrong importer instead of treating it as the other format.
Backup not restored
No data on this device was changed.
Problems found in the file
- savedPlans[2].input.depths[0].depth — Value outside the allowed range: 412.
- settings.ascentSpeed — Value outside the allowed range: 400.
- tanks — Too many entries in this list (600 > 500).
Example of a file-validation report from the app.
Accuracy
Tested against a reference. Clear about the limits.
DecoLab checks its calculations against a reference implementation with regression tests. That checks software consistency, not the safety of an individual dive. Educational approximations are labelled in the app, so you know what you are comparing.
Regression-tested against the reference
The six calculation engines are ported from a reference TypeScript implementation. Regression tests compare time to surface, total runtime, stops, no-decompression limits, CNS, OTU and average depth. Differences in the tested results are flagged, including changes to stop times.
Calculations separate from the interface
The calculation library is written in Dart, without Flutter dependencies. It can be tested independently of the interface; changing the display does not change the underlying equations.
RGBM, with its limitations stated
DecoLab's RGBM implementation uses published equations by Bruce Wienke. It is labelled as an educational approximation, not a reproduction of a particular dive computer's proprietary implementation. The source documents its scope and limitations.
Warnings in your language
The engines return warning and error codes with the relevant values. The interface turns these into messages in all 18 supported languages, including safety-critical warnings.
Before you plan a dive
DecoLab is a planning and teaching tool, not a dive computer or a substitute for training. Cross-check every plan with a dedicated dive computer and follow the procedures taught for that type of dive. No model guarantees freedom from decompression sickness. Decompression diving can cause serious injury or death; you remain responsible for your dive decisions.
Privacy
Your dive data stays on your device.
DecoLab does not require an account or upload your dive data to a cloud service. Planning data stays local. Sending feedback and opening external links are separate actions you choose to take.
No account required
Start planning without signing up. Your cylinders, settings and saved plans are stored on the device you use.
Local storage, by default
Settings, cylinders, cylinder configurations and saved plans are stored locally, with no automatic cloud backup or synchronisation.
No tracking in the planning tools
The app has no analytics, advertising trackers or automatic crash reporting. It does not send us a record of your dives or how you use the planning tools.
Feedback is your choice
Settings → About & feedback offers a suggestion form and two external links. Submitting feedback sends your message, optional reply address, app version, platform and interface language. It does not automatically attach dive plans, cylinders, settings or a device identifier.
Take a copy with you
Export your settings and plans as a readable JSON backup, or protect the backup with a passphrase. Keep the file somewhere safe; there is no automatic cloud copy.
The NDL screen in a 390 × 844 phone layout.
Settings → About & feedback on a phone. The suggestion form sends only the feedback and app details described in the privacy policy.
Get DecoLab
Room to plan, on any screen
The layout adapts to your space: one column and a navigation drawer on a phone, an icon rail in a narrower desktop window, and multi-column panels on a wide screen.
18 languages
Arabic, Bengali, Czech, German, English, Spanish, French, Hindi, Indonesian, Italian, Japanese, Korean, Polish, Portuguese, Russian, Turkish, Vietnamese and Chinese. Planning errors and safety-critical warnings are available in every supported language, and the Arabic interface reads from right to left.
Web
Open the full app in your browser. Your data is stored in that browser; once loaded, the planning tools can run offline.
Android
In closed testing on Google Play. Join the tester list and it installs like any other app.
Support
All the tools. No paid tier.
Every screen, model and language is free, with no advertising or paid features. Has DecoLab saved you an evening of planning? An optional tip helps cover development and distribution costs.
Support DecoLab
Other ways to support DecoLab:
Contributions are entirely optional. They do not unlock features or change how the app works.
