🫁 Oxygen Tank Duration Calculator
Estimate how long a compressed oxygen cylinder will last at a given flow rate, based on the tank’s size and current pressure.
How oxygen tank duration is estimated
Compressed oxygen cylinders come in standard sizes, each with a published “tank factor” (cubic feet of gas released per psi of pressure drop). Combined with the current pressure gauge reading and the flow rate in liters per minute, this factor lets you estimate remaining runtime.
The calculation
The calculator subtracts a small safety reserve (200 psi, a common convention so a tank isn’t run to a true empty of zero) from the current pressure, multiplies the usable pressure by the tank’s conversion factor to get usable gas volume in cubic feet, converts that to liters, and divides by the flow rate in liters per minute to estimate minutes and hours of remaining supply.
This is a general estimation tool for planning purposes only, not medical equipment guidance. Always follow your oxygen equipment manufacturer’s instructions and your healthcare provider’s guidance for actual medical oxygen use, and never rely solely on a calculated estimate when planning oxygen supply for a real trip or emergency.