Dive Time Calculator
Estimate how long your air will last from tank volume, pressure, depth and respiratory minute volume (RMV).
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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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