Pressure Calculator

 

Pressure calculation:

The calculator below allows you to input any one of the seven options, and will calculate the other six for you. That enables you to find the pressure at any given depth, the depth at any pressure, and to convert both depth and pressure measurements in between.

The calculator gives you the pressure in reference to the surface pressure. (Called 'PSI gauge') -or in other words, the pressure with the surface pressure as "zero". Your WTC's and modules are sealed at sea level, which is at 1 atm. The pressure that the WTC / module has to endure is only the difference between the surface pressure, and the pressure at any given depth. It is that pressure that the calculator helps you find.

Tip: If you were to pressurize your modules to say 1 or 2 atm. in reference to sea level, then they could endure going even deeper..

Pressure / Depth   
  PSI
  Atm.
  Bar
  Pascal
  Depth in feet
  Depth in inches
  Depth in meters

Please use dot as decimal point.
Reset by enter new number any where.

Download option: If you would like to have this small HTM-based calculator to run from your own computer, and in your Internet Browser, please feel free to download a 3 Kb zipped version here. 


Pressure calculation, relative pressure:

It might be interesting to calculate the pressure that our sub is subjected to when designing the WTC's.  The formulas for relative pressure calculation for freshwater are as follows:

A) If the pressure inside the WTC is one atmosphere:  Pressure(atm) = ( Depth(Meters)  / 10 )

The WTC's inside pressure will be 1 atm. as long as the WTC has been sealed at sea level. 
The relative pressure that the WTC needs to withstand at 10 ft. (3.05 m.) is thereby 0.305 Atm. 
If you want that in psi, simply multiply the result in atm. by 14.69....... 0.305 x 14.69 = 4.48 psi

B) There is a few golden rules that you can use for estimates:

  • The pressure will increase by 1 psi for every 27.68 US Inches (70.3 cm) you dive. 
  • The pressure will increase by 1 atm for every 33 ft. (10.03 m.) you dive.
  • The pressure will increase by 0.4335147 psi for every ft. you dive.
  • The easiest to remember is this: Pressure(psi) = ( Depth(ft.)  / 2 ).
  • 1 atm = 1.013 bar = 14.69 psi
  • 1 bar = 0.986 atm = 14.50 psi
  • 1 psi = 0.068 atm = 0.068 bar 


Webmaster: Robert Holsting