This calculator suite is designed for recreational and technical divers in Australia, including students completing SDI Open Water, TDI Advanced Nitrox, Decompression Procedures, Trimix and Helitrox courses.
- Maximum Operating Depth (MOD)
- Optimal oxygen fraction for a target depth
- Gas density including helium (He), oxygen (O₂), nitrogen (N₂)
- Equivalent Air Depth (EAD / END) using two narcotic models
- Surface Air Consumption (SAC)
Built by Simple Dive in Blackburn South, Melbourne.
Useful links
Shearwater dive computers
Faber steel cylinders
All Simple Dive articles
Maximum Operating Depth (MOD)
MOD: 33.8 m
Typical planning: PPO₂ 1.2–1.4 for working dives, up to 1.6 for decompression.
Optimal Oxygen Fraction for Target Depth
Optimal O₂: 35.0%
Gas Density with Helium
Density: 5.24 g/L
Recommended: <5.2 g/L for working dives; avoid >6.2 g/L because of increased work of breathing and CO₂ retention.
Equivalent Air Depth (Trimix)
O₂ + He ≤ 100%
EAD (N₂ narcotic): 30.0 m
EAD (N₂ + O₂ narcotic): 30.0 m
N₂ model assumes only nitrogen is narcotic. N₂ + O₂ model assumes both nitrogen and oxygen contribute to narcosis.
SAC Rate Calculator
SAC: 15.0 L/min
Disclaimer: Planning tool only. Always confirm results with a dive computer and a qualified instructor. Never dive beyond your training or comfort level.