Dive Log Statistics Calculator

Instead of analyzing one dive, this calculator works backward from your lifetime logbook totals to estimate trends across your diving career. It first derives your average dive duration by dividing total bottom time by total dive count, then backs out an estimated SAC (Surface Air Consumption) rate from your average tank pressure used, tank volume, average dive time, and the atmospheric pressure at your average depth — essentially inverting the same SAC formula used in real-time gas planning, but applied to averaged historical numbers rather than a single logged dive, so it smooths out variation between easy and demanding dives. That estimated SAC is then bucketed into a rating from excellent (under 12 L/min) to high (over 20 L/min), giving a rough sense of your breathing efficiency relative to typical diver benchmarks.

Separately, the calculator classifies your experience level from total dive count alone (beginner under 30, intermediate 30–100, advanced 100–500, expert 500+) and checks whether your logged maximum depth exceeds a fixed depth ceiling associated with that level, flagging divers who may be pushing depth ahead of their experience curve. A cumulative "depth exposure" figure (average depth times total bottom time) offers a rough proxy for lifetime nitrogen/pressure exposure, though it is not a substitute for real dive-computer logging or DCS risk modeling. Because every output here is reconstructed from summary averages rather than dive-by-dive data, treat the results as directional trends for self-assessment, not a precise or medically validated record.