Back to tools

MOD Calculator

Maximum Operating Depth for Recreational Diving — Nitrox (EAN) and Air.

Gas Parameters
21 % = Air  |  22–40 % = Nitrox (Rec)
PADI recreational limit: 1.4 bar (absolute max: 1.6 bar)

Enter O₂% and max ppO₂, then press Calculate MOD.

MOD Reference Table — Common Recreational Gas Mixes
Gas Mix O₂ % MOD @ 1.2 bar MOD @ 1.4 bar MOD @ 1.6 bar

MOD = (max ppO₂ ÷ fO₂) × 10 − 10  (salt water, 10 m/bar). Always dive within the limits of your certification and training. The recreational ppO₂ limit is 1.4 bar; 1.6 bar is the absolute maximum for technical diving only.

Technical MOD Calculator
Coming Soon

The Technical MOD Calculator will extend this tool for advanced gas mixes including Trimix and Heliox, and will add:

  • Narcotic Depth (END) — Equivalent Narcotic Depth for helium-based mixes
  • Hypoxic Depth — Minimum operating depth for low-O₂ bottom gases
  • Oxygen Window — Optimal ppO₂ range analysis at depth
  • Multi-gas MOD table — Compare multiple trimix blends side by side
  • CNS Clock integration — Estimate oxygen toxicity exposure at planned depth