Dive Tank Air Consumption Calculator
Knowing your air consumption rate helps you plan safer dives. Enter your tank capacity, surface air consumption (SAC) rate, and planned depth to estimate available bottom time.
About this calculator
Estimate how long your scuba tank will last on a dive based on your surface air consumption rate, tank size, and planned depth.
Frequently Asked Questions
What is SAC rate?
Surface Air Consumption rate is how much air you breathe per minute at the surface (1 ATA), usually measured in cubic feet or liters per minute. It varies by diver fitness and experience.
Why does depth affect air consumption?
Air is compressed by ambient pressure at depth, so you consume more actual volume of tank air per minute the deeper you go, even though your breathing rate feels the same.
Why keep a reserve of air?
A reserve, often the 'rule of thirds' or similar, ensures you have enough air for ascent, safety stops, and emergencies before running low.