Gas Management

Nitrox MOD Calculator

Calculate where a gas reaches the selected PPO2 threshold. The result does not determine whether the gas or dive is safe overall.

Extended Range
Extend the calculator range to 200m and show technical gas presets
%

Allowed range: 21 to 100 %.

Oxygen mix presets
ATA

Allowed range: 1 to 1.6 ATA.

Maximum PPO2 presets
m

Allowed range: 1 to 40 m.

Oxygen Percentage
32%
Selected PPO2 threshold
1.4 ATA
Selected PPO2 threshold
Calculated MOD (PPO2 only)
28.1 m

PPO2 threshold only

This result finds the depth where the entered mix reaches the selected PPO2 threshold. It does not assess cumulative oxygen exposure, gas density, narcosis, decompression, equipment, or training limits, and is not permission to use the gas or depth.
About MOD

Maximum Operating Depth (MOD) is the calculated depth where a gas mix reaches a selected partial-pressure-of-oxygen threshold. By itself, it is not a safe-depth determination.

Formula:

MOD = (PPO₂ / (O₂% / 100) - 1) * CF

Where:

  • • PPO₂ = Partial Pressure of Oxygen (ATA)
  • • O₂% = Oxygen percentage in gas mix
  • • CF = Conversion factor (10 for meters)
Common PPO2 Planning References

PPO2 > 1.6 ATA

Outside common scuba planning ranges

PPO2 1.4-1.6 ATA

Often reserved for decompression exposure under applicable training

PPO2 ≤ 1.4 ATA

Common recreational working threshold; not an all-hazards check