This calculator shows how depth, gas mix, and oxygen exposure relate when diving with Nitrox. It calculates the maximum operating depth (MOD) for a given FO₂ and PO₂ limit, and highlights when oxygen exposure exceeds safe levels. For a detailed explanation of how MOD is calculated using Dalton's Triangle and why PO₂ limits matter, see the
Maximum Operating Depth Deep Dive.
Fraction of Oxygen (FO₂) – The percentage of oxygen in the gas mixture.
Partial Pressure of Oxygen (PO₂) – The pressure exerted by oxygen in the mixture.
The table also includes Equivalent Air Depth (EAD) to help visualize how Nitrox affects potential nitrogen narcosis. Even though Nitrox reduces nitrogen loading, dives can still be narcotic at depth — especially below 100 feet.