Nitrox Calculator
Calculate your Maximum Operating Depth, compare Air and Nitrox no-decompression limits, and see how your oxygen percentage changes your dive.
AIR VS NITROX
See what changes underwater.
Select your oxygen percentage and ppO₂ limit. The graph uses SSI Combined Air/EANx Dive Tables. EAN32 and EAN36 use the dedicated SSI columns; other mixes use SSI Equivalent Air Depth.
SSI table no-decompression limits
Smooth lines show the trend between SSI reference points; displayed NDL values still follow SSI’s conservative table-planning rule.
EAN32 at a selected ppO₂ of 1.4 bar.
Air: 40 min · EAN32: 50 min
ppO₂ at this depth: 0.96 bar · EAD: 16 m
+25% table NDL at this depthA quick reference, not a dive plan.
This tool uses SSI’s Combined Air/EANx Dive Tables for no-decompression limits. EAN32 and EAN36 use their dedicated SSI columns. Other mixes are converted to Equivalent Air Depth before using the SSI Air table. A dive computer may still display different values because it calculates your actual profile in real time.
Analyse your gas, set the correct mix on your computer and stay within your training and computer limits.
Reference: SSI Combined Air/EANx Dive Tables and current SSI Enriched Air Nitrox training materials.
Common questions
What is the MOD of EAN32 at a ppO₂ of 1.4 bar?
Using the standard seawater MOD calculation, EAN32 reaches a calculated MOD of approximately 33.8 metres at a ppO₂ limit of 1.4 bar.
Does Nitrox let you dive deeper than air?
No. A higher oxygen fraction can reduce nitrogen exposure, but it also creates a shallower oxygen-limited Maximum Operating Depth for the selected ppO₂.
Why can my dive computer show a different NDL?
This calculator uses SSI table-planning values. Dive computers calculate your profile dynamically, so the NDL shown on a computer may differ from a traditional table value.
What does Equivalent Air Depth mean?
Equivalent Air Depth converts a Nitrox depth into an air depth with equivalent nitrogen exposure. SSI uses this method when planning a mix other than the dedicated EAN32 and EAN36 table columns.