### How to Calculate Oxygen Tank Duration - Health FAQ

Apr 02, 2016·Determine the flow rate. The flow rate is prescribed by the physician and is expressed in liters per minute. As an example, assume 0.5 liters/minute. Calculate the duration of flow using the formula: Duration is the available liters divided by the flow rate. Continuing with the example numbers: Duration = 288/0.5 = 576 minutes. Source