Oxygen Tank Duration Calculator
Estimate how much time is remaining in your medical oxygen cylinder.
D Cylinder (Factor 0.16)
E Cylinder (Factor 0.28)
M Cylinder (Factor 1.56)
G Cylinder (Factor 2.41)
H/K Cylinder (Factor 3.14)
M6 (B) Cylinder (Factor 0.07)
Estimated Remaining Time
How Oxygen Tank Duration is Calculated
Calculating the life of an oxygen cylinder is critical for patient mobility and safety. The duration depends on three main variables: the cylinder size (determined by its "Cylinder Factor"), the current pressure reading on the gauge, and the flow rate prescribed by your physician.
The Formula
Duration (Minutes) = [(Current Pressure – Safe Residual Pressure) × Cylinder Factor] / Flow Rate (LPM)
Understanding Cylinder Factors
Cylinder factors represent how many liters of oxygen are available per PSI for a specific tank size. Common factors include:
- D Tank: 0.16 (Portability tanks)
- E Tank: 0.28 (Standard tall portable tanks)
- M Tank: 1.56 (Large transport tanks)
- H/K Tank: 3.14 (Large stationary tanks)
Realistic Example
If you have a standard E-Cylinder (Factor 0.28) with 1,500 PSI remaining, and your doctor prescribed 2 Liters Per Minute (LPM):
- Subtract the safe residual (usually 200 PSI) from 1,500 = 1,300 PSI.
- Multiply 1,300 by the Factor (0.28) = 364 Liters available.
- Divide 364 Liters by 2 LPM = 182 Minutes.
- Result: 3 Hours and 2 Minutes.
Important Safety Note: This calculator provides an estimate only. Factors such as altitude, temperature, and equipment efficiency can affect actual duration. Always leave a safety margin (residual pressure) of at least 200 PSI and never let your tank reach zero.