***see warning at bottom***

Nitrox Mix Calculator

Mix ( FO2 )

Depth

PO2

EAD
   %    fsw         ATA    ft
PN2: ATA
  
Check off the two values you wish to input. The un-checked values will be calculated.
  • For Best Mix: input Depth and desired PO2.
  • For Maximum Operating Depth: input Mix and desired PO2.
  • PO2s above 1.4 - 1.6 are considered to be dangerous.
  • PN2s above 3.2 - 4.0 are considered to be narcotic.

NOAA Recommended Maximum Oxygen Exposures

PO2
( ATA )

single exposure
( minutes )

24 hour exposure
( minutes )

1.0

 300 300

1.2

 210 240

1.4

 150 180

1.6

 45 150

Sea Level Standard Pressure:
1 atmosphere = 14.696 psia
= 760 mm Hg
= 29.92 inches Hg
= 33.831 ft water ( at 60F )
= 0 ft altitude

Nitrox Fill Calculator

Select
Calculation

Current Fill

 % O2 at psi
Fill Mix % O2 Nitrox % O2 air
Nitrox + Air psi Nitrox + psi air

Target Fill

 % O2 at psi
 
Input your current tank pressure and mix, and the mix from which you will be filling. Then select either your target fill mix and pressure, or input pressures for fill mix and air top-off to calculate the resulting fill.

Some combinations of crazy inputs are checked, others are not. Use your head. Verify all Nitrox mixes personally before using.
Surface Air Consumption Calculator
Time at Depth (Minutes)  Average Depth (feet)  PSI used (PSI) 
Tank volume rating (CU.FT.)  Tank pressure rating (PSI) 
You consumed CU.FT. of gas, and your SAC is CU.FT/Min.

Gas Consumption Calculator

SAC

Depth

Time

Volume
   cft/min    fsw         min.    cft
 
Select the value you wish to calculate, and input the others.

Tank Temperature / Pressure

Starting
Temperature

Starting
Pressure

Ending
Temperature

Ending
Pressure
°F    psig    °F    psig
 
This is an interesting calculation to show how tank pressure varies with temperature. Use it to figure out how much you are losing when a hot-filled tank cools, or what happens when you leave your tanks in a hot car trunk.

Common Unit Conversions

Metric

English
°C °F
meters feet
Bar psi
kilograms pounds
grams ounces
liters cubic feet
kilowatts horsepower
   

Warning:

Results from these calculators are not verified, nor can they be, since the calculations are actually run on your computer, over which Off The Wall Scuba has no control. Round-off error results in minor variations in results between equivalent calculations.

Off The Wall Scuba is not liable for any loss, damage or injury, including DEATH, which may result from engaging in either scuba diving, snorkeling or any of the activities mentioned within this site. These tools and calculators are provided for educational and convenience purposes only and should not be used for planning or conducting actual dives. You must be nitrox certified to conduct dives using nitrox.