Minimum Gas Reserve Calculator
Minimum Gas Reserve (MGR) is the amount of breathing gas you need to safely ascend from your deepest point while assisting a low-on-gas or out-of-gas buddy. This calculator uses the CAT method: Consumption (RMV), Average Pressure (ATA), and Time (at depth and during ascent). By combining these factors, we calculate how much gas volume and pressure (PSI) should be held in reserve to ensure both divers can make a controlled, shared-gas ascent to the surface—even in a stressful situation. A minimum of 500 PSI is always enforced for added safety.
Minimum Gas Reserve Formula using CAT:
\[ \text{MGR} = (\text{RMV} \times 2) \times \text{Average Depth in ATA} \times \text{Time to Ascend} \]