Calculator

Calculator for estimated oxygen cylinder duration using cylinder factor, tank pressure, tank fill replacement level PSIG, and oxygen flow rate.

Cylinder Inputs

Default is 500 PSIG for clinical reserve planning. Board exam note: if no change/replacement value is given, assume 0 PSIG.
This calculation uses oxygen flow rate, not FiO₂.

Estimated Duration

Runtime
Formula:
Solving steps:
Factor
Tank PSIG
Replacement PSIG
Flow L/min
Solving steps:
Usable Pressure:

Summary

Minutes Remaining
0
minutes
Hours Remaining
0
hours
Usable Pressure
0
PSIG after subtraction
EmptyFull
0 min
Interpretation:

Clinical Significance

Tank duration estimates usable oxygen time from cylinder factor, gauge pressure, reserve pressure, and flow. Cylinder factors convert PSIG to liters for each cylinder family; 60 minutes per hour is used when converting minutes to hours and minutes.

This estimate is commonly used during transport, discharge planning, emergency backup preparation, and bedside troubleshooting to determine whether a cylinder contains enough usable oxygen for the intended time period. A 500-PSIG default reserve is good clinical practice because it leaves a practical safety margin for transport delays, handoff time, gauge variation, regulator changes, and unexpected flow increases instead of planning to use a cylinder until empty. The former cylinder-duration-of-flow page used the same core cylinder-factor equation, so this page now serves as the unified cylinder-duration calculator for E and H/K tanks.

This is an estimate rather than an exact runtime. Actual duration may vary with regulator accuracy, gauge accuracy, leaks, high-flow demand, and institutional policy regarding how much pressure should remain before a tank is considered functionally empty and ready for replacement.

References (APA 7th Edition)

  1. Kacmarek, R. M., Stoller, J. K., & Heuer, A. J. (2022). Egan’s fundamentals of respiratory care (12th ed.). Elsevier.
  2. Marino, P. L. (2014). The ICU book (4th ed.). Wolters Kluwer.
  3. West, J. B., & Luks, A. M. (2021). West’s respiratory physiology: The essentials (11th ed.). Wolters Kluwer.