This table gives maximum safe diving depths for given Nitrox blends and
PO2 values. A handy look up chart if cut out and laminated.
Download the table here:
(right-click and select "Save Target As...")
These Nitrox Calculators are PC utilities for calculating various parameters when diving on air or nitrox.
Recreational Nitrox calculator ver 3.0.2:
Advanced Nitrox calculator ver 3.0.2:
Warning: You must be a qualified Nitrox diver to dive on Nitrox. The breathing of Nitrox underwater has
its own inherent dangers and may lead to convulsions and drowning.
This application will calculate the amount of gas in
a filled SCUBA cylinder, the buoyancy of the
cylinder at the start of a dive, at the end of a dive,
on the safety stop and when empty. This tool has
been completely re-written for newer Windows
operating systems.
Changes made to ver 3.0:
- Imperial units option added.
- Manifold used option added.
- Total weight of gas used calculation added.
- Total amount of gas used calculation added.
Useful conversion data
Below is some useful data for when changing between steel and aluminium cylinders or
changing between salt and fresh water. The data refers only to the cylinder, valves,
manifold and gas contents. It does not refer to a divers overall buoyancy.
Cylinder buoyancy figures
Cylinder - pressure
Salt water
Fresh water
Steel 12.2 litre - 232 bar
-3.43 kg
-3.85 kg
Steel 12.2 litre - 50 bar
-0.76 kg
-1.18 kg
Aluminium "12 litre*" - 200 bar
-0.69 kg
-1.18 kg
Aluminium "12 litre*" - 50 bar
+1.3 kg
+0.81 kg
From the above you can see that when using exactly the same SCUBA equipment but
changing from a UK 12.2 litre steel cylinder to a "12 litre Red Sea" aluminium cylinder
an extra 2.7 kg is required on the weight belt. This is due the difference in water density,
difference in the density of the different metals, different water capacities of the cylinders
and difference in fill pressures.
* note: The aluminium cylinders used in the Red Sea and commonly referred to as "12 litre"
are similar to US 80 cubic feet cylinders. These cylinders have a water capacity of approx.
11.1 litres and a max fill pressure of 204 bar (= 3000psig).
