Oxygen Calculator

Oxygen Cylinder Duration Calculator

D Cylinder (0.16) E Cylinder (0.28) M Cylinder (1.56) G Cylinder (2.41) H / K Cylinder (3.14) Select the type of oxygen tank being used.
Standard safety margin is 200 PSI.

Estimated Remaining Time

How to Use the Oxygen Cylinder Duration Calculator

This oxygen calculator helps medical professionals and patients estimate how long an oxygen tank will last based on the current tank pressure, the flow rate prescribed by a physician, and the specific size of the cylinder. Understanding tank longevity is critical for planning travel, patient transport, or ensuring a continuous supply of medical-grade oxygen.

The Calculation Formula

The standard formula used in clinical settings to determine the duration of flow for an oxygen cylinder is:

Duration (Minutes) = [(Current PSI – Safe Residual) × Cylinder Factor] / Flow Rate (LPM)

Oxygen Cylinder Factors

Different tank sizes have specific "factors" that represent the volume of oxygen stored per PSI. Common factors include:

  • D Cylinder: 0.16 (Small portable tank)
  • E Cylinder: 0.28 (Standard portable tank on wheels)
  • M Cylinder: 1.56 (Intermediate size)
  • G Cylinder: 2.41 (Large stationary tank)
  • H/K Cylinder: 3.14 (Large industrial/medical tank)

Practical Example

Suppose you have a standard E Cylinder with a gauge reading of 1500 PSI, and the patient is set to 2 Liters Per Minute (LPM). Using a standard safety residual of 200 PSI:

  1. Subtract residual: 1500 – 200 = 1300 PSI usable pressure.
  2. Multiply by E factor: 1300 × 0.28 = 364 liters available.
  3. Divide by flow rate: 364 / 2 = 182 minutes.
  4. Convert to hours: 3 hours and 2 minutes.

Important Safety Note

Always ensure you have a backup oxygen supply. Variations in temperature, tank condition, and regulator accuracy can affect actual duration. It is highly recommended to change or refill the tank before it reaches the 200 PSI safety residual limit.

function calculateOxygenDuration() { var factor = parseFloat(document.getElementById("tankFactor").value); var psi = parseFloat(document.getElementById("psiReading").value); var flow = parseFloat(document.getElementById("flowRate").value); var residual = parseFloat(document.getElementById("safeResidual").value); var resultDiv = document.getElementById("oxygenResult"); var timeDisplay = document.getElementById("timeDisplay"); var minuteDisplay = document.getElementById("minuteDisplay"); if (isNaN(psi) || isNaN(flow) || isNaN(residual) || flow <= 0) { alert("Please enter valid positive numbers. Flow rate must be greater than zero."); return; } if (psi <= residual) { timeDisplay.innerHTML = "0 Hours 0 Mins"; minuteDisplay.innerHTML = "Warning: Pressure is below safe residual level."; resultDiv.style.display = "block"; return; } // Logic: [(PSI – Residual) * Factor] / Flow Rate var totalMinutes = ((psi – residual) * factor) / flow; totalMinutes = Math.floor(totalMinutes); var hours = Math.floor(totalMinutes / 60); var mins = totalMinutes % 60; timeDisplay.innerHTML = hours + "h " + mins + "m"; minuteDisplay.innerHTML = "Total time: " + totalMinutes + " minutes remaining."; resultDiv.style.display = "block"; resultDiv.scrollIntoView({ behavior: 'smooth', block: 'nearest' }); }

Leave a Reply

Your email address will not be published. Required fields are marked *