Dive Time Calculator
Estimate how long your air will last from tank volume, pressure, depth and respiratory minute volume (RMV).
Input
Estimate roughly how long your air will last within no-decompression limits, using tank volume, starting pressure, depth and your respiratory minute volume (RMV). Actual consumption varies widely with exertion, water temperature, experience and current, so treat the result as a rough guide only.
Result
Estimated dive time
~39min
39m 17s (until your reserve pressure is reached)
Dive time
~39 min
Consumption at depth
42.0 L/min
Ambient pressure
2.8 ATA
Calculation breakdown
| Usable gas (surface equivalent) | 1,650 L |
| Ambient pressure (depth ÷ 10 + 1) | 2.8 ATA |
| Consumption at depth (RMV × ambient pressure) | 42.0 L/min |
| Dive time | ~39 min |
* This is a simplified estimate that does not account for no-decompression limits (NDL), safety stops or out-of-air margins. On a real dive, keep a generous reserve and always follow your dive computer and your certifying agency's safety standards.
How it works
- Consumption (L/min) is calculated as RMV × (depth ÷ 10 + 1). The deeper you go, the higher the ambient pressure, so the same breathing uses more air.
- Usable air is (starting pressure − reserve pressure) × tank volume, and dividing this by the consumption at depth gives the estimated dive time.
- RMV varies greatly between individuals and changes with exertion, water temperature, current, experience and stress. Knowing your own typical value from past logs improves accuracy.
- Keep a generous reserve pressure (for example around 50 bar) for ascent, safety stops and emergencies.
- This is a simplified estimate that ignores no-decompression limits (NDL), safety stops and out-of-air risk. It is not a dive plan; always follow your dive computer and your certifying agency's safety standards.
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Dive Time Calculator