Best mix calculator: nitrox and trimix with END
Find the blend for a planned depth: as much oxygen as your ppO₂ limit allows, and helium only if your END limit needs it.
Metric units: m, bar, L, kg.
Result
Dense gas: 5.3 g/l at 30.0 m, over the advised 5.2 g/l. Add helium or plan shallower.
- Best mix
- EAN35
- Oxygen
- 35%
- Helium
- 0%
- Equivalent narcotic depth (END)
- 30.0 m
- MOD of this mix at ppO₂ 1.4
- 30.0 m
- Gas density at depth
- 5.3 g/l
The form starts on example values.
How it works
The best mix is the MOD calculation the other way round: the oxygen fraction is the one that reaches your ppO₂ limit exactly at the target depth. If air at that depth is more narcotic than your END limit allows, helium replaces part of the nitrogen until the equivalent narcotic depth is back within it.
Blends are filled and measured in whole percent, so oxygen is rounded down and helium up, which keeps both limits on the safe side. Gas density is shown because dense gas makes breathing hard work; 5.2 g/l or less is the usual advice. A hypoxic mix cannot be breathed at the surface and needs a travel gas.
Plan the mix and the fill in Loggerfish →
The same calculations run in the Loggerfish app.