SAC Rate Calculator
Surface Air Consumption: how many litres of gas you breathe per minute at the surface. Compute it from a single dive's data to plan gas reserves and turn pressures for future dives.
Dive data
From your dive computer log. Not max depth.
Results
SAC rate (surface)
— L/min
This is the gas you'd breathe per minute at the surface, your baseline consumption.
RMV at average depth
— L/min
What you actually consumed at — m average.
Total gas used
— L (surface equivalent)
Typical recreational range: 12–25 L/min. Tech divers under task loading often hit 25–35 L/min. Use your worst dive for gas planning, not your best.
Common questions
What is a good SAC rate for scuba diving?
It varies a lot, but a relaxed, well-trimmed recreational diver is often around 12 to 18 litres per minute. Fitness, trim, workload, and stress all move it; the number that matters is your own, measured across real dives.
How do you calculate SAC rate?
SAC equals (gas used in bar times cylinder volume in litres) divided by (dive time in minutes times average absolute pressure). Average absolute pressure is average depth in metres over 10, plus 1. The result is litres per minute at the surface.
What is the difference between SAC and RMV?
SAC is often quoted in bar per minute for one specific cylinder, while RMV is in litres per minute and is cylinder-independent. This tool works in volume, so the figure transfers between tanks.