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Oxygen Tank Duration Calculator

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What is oxygen tank duration?Using the oxygen tank duration calculatorOxygen tank duration formulaOxygen tank duration chartHow to calculate oxygen tank durationFAQs

Other than being the oxygen tank duration calculator, there are many different names for this tool is famous as:

  • Oxygen calculator;
  • Oxygen flow rate calculator; and
  • O2 tank calculator.

Our tool provides information on how long an oxygen tank will last based on size and flow rate. Picturing an oxygen tank immediately brings to mind a hospital or healthcare facility, which signifies its value.

If you are interested in knowing how to calculate the oxygen tank duration? or what an oxygen tank size chart is?, then we encourage you to continue with the article. It is sure to enhance your knowledge.

What is oxygen tank duration?

The oxygen tank duration estimates the length of time that an oxygen cylinder can deliver oxygen gas at a particular flow based on the pressure inside the tank and the size of the tank.
This is known to be an essential factor for different medical facilities.

Oxygen tanks are one of the most critical elements in hospitals. It is needed for patients who need oxygen therapy in emergency rooms. Furthermore, it is also required for surgical procedures for patients who need oxygen on a long-term basis. Due to COVID-19, along with ventilators, oxygen tanks have become an integral part of hospitals for their assistance in the treatment.

Oxygen therapy, provided via oxygen tanks, treats not only breathing problems but also insomnia, emphysema, and sleep apnea.

Based on the critical situations that occurred, we prepared a COVID mortality rate calculator. You may want to give it a try.

Using the oxygen tank duration calculator

As significant as oxygen duration is, the goal of making the oxygen tank duration calculator is to make the calculations easier for you, as there are so many hard things to do in life.

The calculations only need a few important variables. Let's take a look at how to use the tool.

  1. You first need to select the size of the oxygen tank. They are displayed in the alphabet, along with their oxygen capacity in liters.

  2. The next thing to input is the pressure of the oxygen tank in any unit of pressure. You have a list to choose from.

  3. After that, enter the flow rate of the tank.

  4. Once you input the values correctly, the tool determines the time remaining or the duration for which the oxygen in the tank lasts. The default unit is minutes, but you can select any other from the list.

We told you it was easy.

Remember how the teachers always elaborated with an example in school, and we would have fun while learning? Based on that idea, now is the time to consider an example to clarify things.

For instance, you select the tank size as D (340 L). You also input the tank pressure equal to 7500 psi and the flow rate equal to 5 LPM. The result is a duration of 4 hours. With the given credentials, the oxygen tank will last you or your patient 4 hours.

Our oxygenation index calculator gives an accurate way of measuring the ability of the lungs to transfer oxygen from the air we breathe into our blood. We suggest you check it out.

💡 The average person requires approximately 0.84 kg of oxygen per day for survival.

Oxygen tank duration formula

The oxygen tank duration formula depends on the pressure in the tank, the flow rate, and the tank's size. Each tank size corresponds to a conversion factor.
The formula looks as follows:

Tank duration = PSIG × conversion factor / flow rate


  • PSIG — The gas pressure in the tank; and
  • Conversion factor — A numeric value corresponding to each size.

We have a flow rate calculator in case you want to know how to determine the flow rate of different substances.

Oxygen tank duration chart

The oxygen tank duration chart, also known as the oxygen tank size chart, contains the conversion factor against different sizes.

The sizes are generally given as the letters of the alphabet, along with the volume in liters.

Each size is assigned a numeric value known as "the conversion factor". This value is part of the oxygen tank duration formula.

Tank size


Conversion factor


170 L



340 L



680 L



1360 L



4100 L



6600 L



6800 L



7100 L



7500 L


How to calculate oxygen tank duration

Have you ever been in a situation where you needed to do some calculations but realized that you didn't have your phone or favorite tool available? What do you do then? Grab a pen and paper.

It is time to grab that pen and paper, as we will learn how to calculate the oxygen tank duration; now that we are familiar with the duration chart and formula.

Follow the steps below and calculate your worries away!

  1. Note down the size of the oxygen tank.
  2. Use an oxygen tank duration chart to determine the conversion factor.
  3. Multiply the conversion factor by the PSIG value.
  4. Divide the result from step 3 by the flow rate.
  5. You have the duration in minutes. There is a list of units to choose from.

Is oxygen tank duration and flow the same thing?

No, they are not the same.

Oxygen tank duration indicates the total time the oxygen in the tank will last based on the size and flow of the tank.

Whereas the oxygen tank flow signifies the speed at which the oxygen flows from the tank.

How can I calculate the oxygen tank duration?

To calculate the oxygen tank duration, follow the steps below:

  1. Note the size of the oxygen tank.
  2. Use a chart to determine its conversion factor.
  3. Multiply it by the pressure of the tank.
  4. Divide the result by the oxygen tank flow rate.
  5. The result is the duration the oxygen in the tank will last.

How long will 680 liters of oxygen last?

The estimated time it may last is 8.6 hours, considering the flow rate is 3 LPM and the pressure in the tank is 5500 psi.

680 liters is the capacity of a size E oxygen tank.

Is the tank size important for oxygen tank duration?

Yes, the tank size is as important as any other factor.

How long the tank is going to last is dependent on the size of the tank. The bigger the oxygen tank size, the longer it will last.

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