The other difference you will see is that the tank sizes are for the amount of free gas, not the water capacity. You will probably be diving an AL80 --- about 77 cu ft or 2200 liters. Tank is about 11 liter size, 207 bar.
70 bar per per 1,000 psi is the most convenient conversion.
Full tank = 3000 psi = about 210 bar
Half tank = 1500 psi = about 100 bar
Normal ascent pressure is between 1000 psi / 70 bar and, 700 psi / 50 bar.
The other very useful metric/imperial conversion is that each 10' is 3m.
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On one trip to the Florida Keys I had a buddy from the UK that just absolutely, absolutely could not figure out the PSI/bar conversion. For the shallow Keys dives, what finally worked for him was "in the red, we should be on the boat, or at least at safety stop". In the yellow (1000psi on his rental gear IIRC), "we should be headed back".
It got me to thinking that maybe we ought to just have an SPG that looks like a car fuel/petrol gauge. Full, 1/2, 1/4/ 1/8 Empty!