Technical Support

Oxygen Concentration Calculator

Oxygen Depletion Calculator for Confined Spaces.

The calculation of percentage of oxygen in the air after the evaporation of a volume of liquefied gas – nitrogen or solid CO2 in a confined space.

  • Calculate the volume (Vr m3) of the confined space.
  • Calculate the volume of the released gas (Vg) by multiplying the volume of the liquid nitrogen (in liters) or weight of solid carbon dioxide (in Kg) by the expansion ratio of LN (.682) or the inverse density of CO2 (.552 m3/Kg).
  • Calculate the volume of available oxygen (Vo m3) as 0.2095*(Vr-Vg).
  • Calculate the % oxygen available to breathe as 100*Vo/Vr.
Room Length (meters)
Room Width (meters)
Room Height (meters)
Type of Spill (LN or CO2)
Amount of Spill (liters of LN2 or Kg of CO2)

Volume of Room.

Volume of Released Gas.

Volume of Available Oxygen.

Percent Oxygen Available to Breathe.


  • Uniform mixing of LN or CO2 with room air.
  • No pressure considerations taken.
  • Spill is contained in the room.