Free Tool
Set your altitude, ambient and fill temperatures, configure your banks (O₂, He, Air, with optional volume/pressure tracking), then save a named cylinder for every customer or buddy. Dive Kit returns a numbered fill plan: bleed, add He, add O₂, top with air, with the resulting mix and total gas drawn from each bank.
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Save a cylinder per customer. Get a numbered fill plan for each.
The Blend Planner is built for the way fill stations actually work. The Environment card sets altitude, ambient temperature, and fill temperature so the math accounts for thermal compression after the cylinder cools. The Banks card lists every gas source you have available, Air, O₂, He, or any custom bank, each with optional volume@pressure tracking so you know how much each fill drains from your supply.
The Cylinder card holds the current cylinder's volume, current pressure, residual O₂%/He%, and the target mix and pressure. Quick Fill loads from your saved gas presets. The horizontal cylinder bar at the bottom lets you save and switch between named cylinders, "Bob", "Charlie", "Ronny", so you can line up the day's fills upfront and work through them without losing any configuration. Banks and environment are shared across all cylinders.
The Plan output is a numbered sequence: bleed to a target pressure, add He to a pressure, add O₂ to a pressure, top with Air. Each step explains what changes ("O₂% Change: 1.9% → 48.5%") so you can stop mid-fill and verify with an analyzer. The Result card shows the final mix (e.g. TMX 32/20) at target pressure and the total gas drawn from each bank in litres and bar.
It works in absolute pressure and corrects for fill temperature and altitude, so the cylinder settles at the mix and pressure you planned once it cools. Saved cylinders, banks, and environment persist across app restarts.
Partial pressure blending relies on Dalton's Law: each gas contributes independently to the total pressure. To create a target mix, you add gases sequentially, first the gas with the lowest compressibility (typically helium), then oxygen, then top off with air. Dive Kit works in absolute pressure and corrects for fill temperature and altitude, so the cylinder settles at the mix and pressure you planned once it cools. Like the partial-pressure method itself, it assumes ideal gas behaviour, accurate to within a few percent at normal fill pressures.
Three cards, one cylinder bar, a numbered plan.
Environment & Banks
Set altitude, ambient temperature, and fill temperature so the math accounts for thermal compression after the cylinder cools. The Banks card lists every gas source with optional volume@pressure tracking, so you always know how much each fill drains from your supply.
Multi-cylinder management
The horizontal cylinder bar lets you save and switch between named cylinders, "Bob", "Charlie", "Ronny", without losing any configuration. Each cylinder keeps its own current pressure, residual mix, and target. Quick Fill loads from your saved gas presets. Banks and environment are shared across all cylinders.
Step-by-step plan
Dive Kit returns a numbered fill plan: bleed to a target, add He, add O₂, top with air. Each step shows the resulting O₂% and He% change so you can stop mid-fill and verify with an analyzer. The Result card confirms the final mix at target pressure and the total gas drawn from each bank.
More free dive planning tools in Dive Kit.
Download Dive Kit free on iOS and Android. Gas Blender is included, no account, no ads, no internet required.