SCBA Air Time Calculator
Estimate how long your SCBA air supply will last. Choose your brand to access model-specific cylinder presets.
Select your SCBA brand
Choose your manufacturer below. Each brand page loads model-specific cylinder presets — water volume (L), service pressure (bar), and default reserve — so you can calculate estimated air duration in seconds.
MSA
Calculate SCBA air time for MSA M1 (EN), MSA G1 (NFPA), AirMaXX and AirGo models. Enter cylinder size, starting pressure, reserve, and RMV for a firefighter planning estimate.
→Dräger
Calculate air time for Dräger PSS 7000, PSS 5000, PSS 4000 and PSS 3000 SCBA. Enter cylinder size, starting pressure, reserve pressure, and RMV for a training and planning estimate.
→3M Scott Fire & Safety
Calculate air time for 3M Scott ProPak-FX (EN), Air-Pak X3 Pro (NFPA), and Sigma 2 SCBA models. Select cylinder, enter pressure and RMV for a firefighter planning estimate.
→Interspiro
Calculate air time for Interspiro Incurve, QS II, and SpiroGuide II SCBA models. Select cylinder, enter starting pressure, reserve, and RMV for a firefighter planning estimate.
→Honeywell (Fenzy / Survivair)
Calculate SCBA air time for Honeywell Aeris Confort (Fenzy, EN Standard) and Honeywell TITAN (NFPA). Select cylinder, enter pressure, reserve, and RMV for a planning estimate.
→Spasciani
Calculate air time for Spasciani RN/MK2 SCBA (EN 137 Type 2) and SK Escape Set (EN 1146 EEBD). Select cylinder, enter pressure, reserve, and RMV for a planning estimate.
→Ocenco
Ocenco closed-circuit oxygen escape devices: equipment references and manufacturer documents. No open-circuit SCBA air-time calculation.
→How to Calculate SCBA Air Time
On the fireground, "How much air do I really have left?" is a safety decision, not a theory question. This SCBA Air Time Calculator gives firefighters a quick planning estimate based on cylinder size, starting pressure, reserve pressure, and breathing rate. Use it for training, pre-plans, and drills — not as a substitute for your gauge, SOPs, or officer direction.
The formula is straightforward: usable air (L) = water volume (L) × usable pressure (bar), where usable pressure = starting pressure minus reserve. Dividing usable air by your RMV (Respiratory Minute Volume, L/min) gives estimated minutes. If your workload increases, RMV climbs fast — and your time drops with it.
What this tool is useful for
- Training: Compare light vs. heavy RMV values and see how rapidly time changes under stress.
- Pre-plans: Estimate air needs for long corridors, high-rises, basements, and large-area searches.
- Crew briefings: Build shared understanding of reserve pressure and realistic work rates.
- Gear familiarisation: Compare cylinders (e.g., 6.8 L at 300 bar vs. 9 L at 300 bar) for planning.
Practical RMV ranges for firefighters
- Light work (25–35 L/min): Walking, light overhaul, staged wait, low-stress movement.
- Moderate work (35–55 L/min): Hose advancement, stairclimbing, controlled search.
- Heavy work (55–80+ L/min): High heat, aggressive interior attack, victim rescue, prolonged exertion.
If you have completed an SCBA consumption test, use your personal RMV value in the custom field.
Reserve pressure: what it actually means
Reserve pressure is not "extra air" — it's your planned buffer for egress, unexpected entanglement, disorientation, radio communication, and assisting a partner. The 55 bar reserve shown in some examples is an illustrative input, not a universal alarm or exit threshold. Some departments require higher reserves for high-rise or tunnel operations. Always confirm with your AHJ and training officer.
SCBA Cylinder Size Reference
This table compares simplified training estimates using an illustrative 55 bar reserve and 40 L/min RMV. These are not operational limits. Real durations depend on your actual starting pressure and workload.
| Cylinder | Service pressure | Total air | Usable air* | Est. time @ 40 L/min |
|---|---|---|---|---|
| 6 L | 200 bar | 1,200 L | 970 L | ~24 min |
| 6 L | 300 bar | 1,800 L | 1,470 L | ~37 min |
| 6.8 L | 300 bar | 2,040 L | 1,666 L | ~42 min |
| 7 L | 300 bar | 2,100 L | 1,715 L | ~43 min |
| 9 L | 200 bar | 1,800 L | 1,305 L | ~33 min |
| 9 L | 300 bar | 2,700 L | 2,205 L | ~55 min |
* Usable air = total air minus reserve (55 bar × cylinder water volume). Actual duration will vary. Use the calculator above for your exact values.
Frequently Asked Questions
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