Oxygen Duration Calculator

Calculate how long your supplemental oxygen supply will last based on altitude, flow type, and number of occupants. Includes FAR 91.211 requirements.

Bottle Volume

ft³

Portable: 22 ft³, Standard: 48 ft³, Large: 77 ft³

Current Pressure

PSI

Planned Altitude

Number of Users

Flow Type

Tab to move between fields

Oxygen Duration

906 min

Duration (hours)

15.1 hr

FAR 91.211 Requirement

FAR 91.211: All occupants must use supplemental O₂ above 14,000 ft.

Total Flow Rate1.5 LPM

Available Oxygen1,359 L

Tank Level100%

How to Use This Calculator

How the result changes with Planned Altitude

Planned Altitude	Oxygen Duration	Duration (hours)	FAR 91.211 Requirement
15,000	906 min	15.1 hr	FAR 91.211: All occupants must use supplemental O₂ above 14,000 ft.
18,000	340 min	5.7 hr	FAR 91.211: All occupants must use supplemental O₂ above 14,000 ft.
15,000	453 min	7.6 hr	FAR 91.211: All occupants must use supplemental O₂ above 14,000 ft.

Bottle Volume: Oxygen bottle capacity in cubic feet. Common sizes: 22, 48, 77 ft³.
Current Pressure: Current oxygen bottle pressure gauge reading.
Full Bottle Pressure: Maximum rated pressure when full.
Planned Altitude: Altitude where oxygen will be used. Higher = more flow required.
Number of Users: How many people sharing this oxygen supply.
Flow Type: Continuous flow (nasal cannula) uses more O₂. Demand regulators conserve ~50%.

Flow Rate Per Person
Based on altitude and regulator type
15,000 ft, continuous flow = 1.5 LPM per person
Total Flow Rate
Total = Flow Rate × Number of Occupants
1.5 × 1 = 1.5 LPM total
Available Oxygen
Available = Volume × 28.32 × (Current PSI ÷ Max PSI)
48 × 28.32 × (1800 ÷ 1800) = 1359 liters
Oxygen Duration
Duration = Available Liters ÷ Total Flow Rate
1359 ÷ 1.5 = 906 minutes (15.1 hours)