Gas Consuption Calculation (bar/min Psi/min) Wrong!!!

The gas consumption is normalized to surface pressure. By doing this you can easily compare your consumption on different parts of the dive and you can see how hard you're breathing. If it wasn't normalized then it would be dominated by the depth.

If you want the to see how much gas you've used then you need to multiply with the ambient pressure. In your case I would guess the average depth is around 19-20 meters, since 3.8 / 1.3 = 2.9.

You can also use this to calculate expected consumption on future dives, if you're doing a 30 m dive then you would likely use around 1.3*4 = 5.2 bar/min at depth and if you stay at 10 m then it would be 1.3 * 2 = 2.6 bar/min.

Thanks for reply, you are correct. I was thinking that only metrics like SAC was normalized.