Air Consumption (SAC / RMV) Calculator

Work out your surface-equivalent air consumption from tank pressure, size, average depth and dive time — the number you need to plan gas for the next dive.

Tank

Tank used

Tank volume(L)

Water capacity in litres — stamped on the tank or listed by the shop.

The dive

Start pressure(bar)

End pressure(bar)

Average depth(m)

Use the average depth from your dive computer.

Dive time(min)

Air consumption (surface equivalent / RMV)

12.5L/min

Experienced range. Results are estimates. Real values vary with the individual, the equipment and the conditions on the day.

SAC (this tank)

1.25 bar/min

Pressure used

100 bar

Ambient pressure

2 ata

Note: the L/min figure is often called SAC, but strictly it is RMV — surface-equivalent respiratory minute volume. Pressure-based SAC (bar/min) depends on tank size, so it cannot be compared across different tanks. Use RMV when comparing between divers.

For education and planning support only

This does not replace dive training, a dive computer, or the judgement of the guide or instructor on site. Always follow your certifying agency's training and your own equipment.