Nitrox Maximum Operating Depth (MOD)
Nitrox maximum operating depth = 10 x (PO2max / FO2 - 1) meters of sea water; below the MOD the inspired PO2 exceeds the CNS oxygen-toxicity limit.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Oxygen fraction FO2
- 0.32
- PO2 limit
- 1.4 bar
Result: Maximum operating depth 33.8 m (FO2 0.32 at PO2 1.4 bar).
The tool opens with these values already filled in. Replace them with your own.
What the result means
- meters
- 10 x (PO2max / FO2 - 1). Below the MOD the inspired PO2 exceeds the CNS oxygen-toxicity limit (typically 1.4 bar working). A depth limit, not a diagnosis.
What you enter
- Oxygen fraction FO2 (e.g. 0.32 for EAN32)
- PO2 limit
How this is calculated
Maximum operating depth (nitrox) = 10 x (PO2max / FO2 - 1) m (dive-medicine standard; see Wikipedia "Maximum operating depth" and TDI/SDI nitrox references). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.