Free Tool
Set your starting cylinder (volume, current pressure, residual mix), then add gases one step at a time, O₂, He, Air, or any custom mix. Dive Kit shows the resulting O₂/He/N₂ at each step and the final mix at target pressure.
Free download, no account needed
The opposite question to the Blender, useful when you know what you added, not what you wanted.
The Mix Calculator answers a different question to the Blender. The Blender is goal-driven: "I want EAN50, what do I add?" The Mix Calculator is sequence-driven: "I added 50 bar of air, then topped with 5 bar of O₂, then 5 bar of Heliox 70/30, what do I have now?"
Useful at the fill station when you need to verify what's actually in a cylinder after a sequence of fills, or when you're working out a fill plan that doesn't quite match a Blender recipe (e.g. limited supply of one bank gas).
Under the hood it uses Dalton's Law for partial pressures, the same as the Blender, so the result matches what an analyzer would read.
Each gas contributes to total pressure independently. When you add 5 bar of O₂ to a cylinder already at 50 bar of air, the new partial pressure of O₂ is 0.21 × 50 + 1.00 × 5 = 15.5 bar in a 55-bar total, giving FO₂ ≈ 28.2%. The Mix Calculator chains this calculation across every step, so the result matches what an analyzer would read.
Setup, then add gases, see what you have at every step.
Setup
Set the current cylinder's volume, current pressure, and what's already in it (residual O₂% / He%). Then add the first gas, pick from O₂, He, Air, or any custom mix, with its add pressure. The Add Gas button drops it onto the step list.
Steps & Result
Each step in the list shows what was added and at what pressure. The Result card shows the final mix (e.g. TMX 22/11) at the target total pressure. Tap any step to edit or remove it.
More free dive planning tools in Dive Kit.
Download Dive Kit free on iOS and Android. Mix Calculator is included, no account, no ads, no internet required.