Oxygen Tank Duration Calculator
Tap a cylinder size, or enter the factor (litres of oxygen per psi). E is 0.28; adjust for your cylinder.
What is Oxygen Tank Duration Calculator
An oxygen tank duration calculator estimates how long a cylinder will last at a set flow. It multiplies the gauge pressure by the cylinder factor (the litres of oxygen the tank holds per psi) and divides by the flow rate. The formula is time in minutes = gauge pressure (psi) times cylinder factor divided by flow (L/min). Common US factors are D 0.16, E 0.28, M 1.56, G 2.41, and H 3.14.
How to use
- Read the gauge pressure in psi from the regulator and enter it.
- Enter the flow rate in litres per minute.
- Pick a cylinder size, or type the cylinder factor for your tank.
- Read the time remaining in hours and minutes.
When to use it
Wheeling a patient to imaging on an E cylinder at 2000 psi and 2 L/min? Enter those and you get 280 minutes, about 4 h 40 min. Knowing the run time tells you whether the tank will outlast the trip or needs swapping first.
Frequently asked questions
What is the formula for oxygen tank duration?
Time (min) = gauge pressure (psi) × cylinder factor ÷ flow (L/min). For an E cylinder (factor 0.28) at 2000 psi running 2 L/min, that is 2000 × 0.28 ÷ 2 = 280 minutes.
What is the cylinder factor?
It is the litres of oxygen a cylinder delivers per psi of gauge pressure, and it depends on tank size: D 0.16, E 0.28, M 1.56, G 2.41, H 3.14. For a cylinder rated in other units, the factor is its full capacity in litres divided by its full pressure.
Should I run the tank to zero?
No. Change the cylinder well before it empties. Many services keep a safe residual of around 200 psi so the tank is never fully drained, so the usable time is a little shorter than the raw calculation.
Can I share this tool with my inputs pre-filled?
Yes. The URL updates automatically as you type. Copy it from the address bar or use the Share button — anyone who opens the link will see your exact inputs ready to go.
Related tools
A-a Gradient Calculator
Calculate the alveolar-arterial oxygen gradient from FiO2, PaO2 and PaCO2, and compare it to the expected value for age. Free and instant.
How Old Am I? Age Calculator
Find out exactly how old you are with this free age calculator. Enter your date of birth and get your age in years, months, days, zodiac sign, and more.
Anion Gap Calculator
Calculate the serum anion gap from sodium, chloride and bicarbonate, with optional potassium and albumin correction, to screen for metabolic acidosis.