Nitrox MOD & best-mix calculator

Work out the limits of any nitrox mix in seconds. DecoLog's gas lab gives you maximum operating depth (MOD), the best mix for a target depth, and equivalent air depth (EAD) — for salt or fresh water. It's free and works offline.

What is MOD?

Maximum Operating Depth is the deepest you can take a mix before its oxygen partial pressure (ppO₂) climbs past a safe limit. The standard limits are 1.4 bar for the working phase of a dive and 1.6 bar for resting decompression stops. Richer mixes (more oxygen) have shallower MODs — DecoLog shows the depth for both limits.

Best mix for the depth

Flip it around: given the depth you plan to dive, what's the richest nitrox you can breathe? That's your best mix — it maximises no-decompression time and minimises nitrogen loading while staying inside your ppO₂ limit.

Equivalent air depth (EAD)

EAD tells you which air depth has the same nitrogen partial pressure as your nitrox at depth — so you can read no-stop limits and narcosis against familiar air figures.

From your first nitrox dive onward

These are the everyday tools every diver needs, and they live in the same app that scales up to trimix, decompression and CCR planning — so DecoLog grows with you from your first EANx course to technical diving.

⚠ DecoLog is a planning aid, not a substitute for training. Always analyse your gas, confirm its MOD, and dive within your certification.