To use the altitude diving calculator, simply select the units, type in the elevation and diving depth, and get the result.
How to read the results
Depending on the diving depth you entered, and the elevation you’re at (for altitude diving), you will receive different results in bar, psi, and kPa.
Switching from saltwater to freshwater will give you slightly lower pressures, as the density is smaller.
Atm measurements are more or less identical to bar.
How to determine the water pressure at altitude
For quick calculations of the water pressure at altitude, add 1 bar/atm per 10m / 33ft of water depth to the 1 bar/atm of atmospheric pressure and subtract 0.1 bar/atm per 1,000m/3,300ft elevation. Therefore, when diving at 20m/66ft depth in a mountain lake at 2,000m/6,600ft elevation, you’ll experience 3.8 bar/atm of pressure.
If you follow this quick approach, you should get by just fine. For more accurate calculations, use the scuba diving water pressure calculator above.
Here are some examples for you to practice. You’ll find all measurements in metric and imperial units and for simplicity’s sake, we assume freshwater and saltwater to be identical in pressure and density.
|0m / 0ft||Sea level (0m / 0ft)||1bar / 1atm / 14.7psi|
|0m / 0ft||1,000m / 3,300ft||0.9bar / 0.9atm / 27.8psi|
|10m / 33ft||Sea level (0m / 0ft)||2bar / 2atm / 29.3psi|
|10m / 33ft||2,500m / 8,250||1.75bar / 1.75atm / 25.63psi|
|16m / 53ft||Sea level (0m / 0ft)||2.6bar / 2.6atm / 38psi|
|16m / 53ft||3,000m / 9,900ft||2.3bar / 2.3atm / 33.6psi|
|20m / 66ft||Sea level (0m / 0ft)||3bar / 3atm / 43.8psi|
|20m / 66ft||3,000m / 9,900ft||2.7 bar / 2.7atm / 39.5psi|
|35m / 116ft||Sea level (0m / 0ft)||4.5bar / 4,5atm / 65.7psi|
|35m / 116ft||500m / 1650ft||4.45bar / 4.45atm / 65psi|
As you can see, using metric measurements like bar and m is a lot more intuitive than imperial ones due to the decimal base (multiples of 10).
However, if you practice enough, you’ll be able to do the same in any units of measurement you choose.
Learn more about altitude diving
To learn in-depth about altitude diving, check out our ultimate altitude diving guide 2023!
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