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SCUBA Gas Consumption Planner – Online SAC Rate & Tank Volume

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SCUBA Gas Planner

Dive Parameters
Tank specs: 11.1 L · 200 bar · ~2,220 L gas
Typical: 1.0–2.5 bar/min
Auto-calculated from SAC
Safety margin (min 50 bar / 500 psi)
ATA at depth: 2.80
150 bar usable
Reserve: 50 bar Usable: 1,665 L
Results
Estimated Dive Time
--
minutes
Depth Consumption Rate
--
bar/min at depth
Usable Gas
--
L (surface equivalent)
Gas Consumption Rate
--
L/min at depth
Good safety margin
Gas usedReserve
Quick Reference – Time at Common Depths
DepthATATime AvailableConsumption Rate
Calculate Your SAC from a Dive

Enter data from a recent dive to calculate your Surface Air Consumption rate.

From dive computer (or ~2/3 max depth)
Your SAC Rate
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bar/min
Your RMV
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L/min
SAC Reference Guide
Diver LevelRMV (L/min)SAC on AL80 (bar/min)
Beginner20–281.8–2.5
Intermediate15–201.4–1.8
Experienced12–161.1–1.4
Very Efficient8–120.7–1.1
Working/Current25–35+2.3–3.2+

SAC depends on tank size. RMV is universal. Lower RMV = better air efficiency.

Full Depth-Time Reference Table

Based on your current planner settings. Depths shown from 5m to 50m.

Depth (m) ATA Consumption Rate Max Time (min) Gas Used /10min Status
Frequently Asked Questions

SAC is the rate at which you consume air at the surface (1 ATA). It's measured in bar/min (metric) or psi/min (imperial). Your actual consumption at depth is higher due to increased pressure – at 10m depth you breathe air at 2x the surface pressure, so consumption doubles. Knowing your SAC helps plan gas requirements for any dive.

SAC (Surface Air Consumption) is tank-specific – it tells you how many bar/psi you use per minute. This depends on your tank size. RMV (Respiratory Minute Volume) is tank-independent – measured in L/min or cuft/min, it represents actual air volume consumed. RMV is the universal metric to compare efficiency across different tank sizes. Formula: RMV = SAC × Tank Volume (for metric).

Several factors affect air consumption: buoyancy control (proper weighting reduces effort), trim and streamlining (reduces drag), breathing technique (slow, deep breaths), fitness level, relaxation (anxiety increases breathing rate), water temperature (cold increases consumption), and proper gear fit. Regular diving and conscious practice are the best ways to improve.

For recreational diving, a common rule is to surface with 50 bar (500 psi) remaining. The Rule of Thirds (1/3 out, 1/3 back, 1/3 reserve) is used in technical diving and overhead environments. Always plan your dive conservatively – unexpected currents, navigation issues, or buddy emergencies can quickly increase gas consumption. Never push your gas limits.

Gas consumption is directly proportional to absolute pressure (ATA). At 10m/33ft (2 ATA), you consume 2× your surface rate. At 20m/66ft (3 ATA), it's 3×, and at 30m/99ft (4 ATA), it's 4×. This means a 30-minute dive at 30m uses as much gas as a 2-hour dive at the surface. This exponential relationship is why deeper dives require much more careful gas planning.

Common recreational tanks: AL80 (11.1L, ~2,220L gas) – standard for most warm-water diving; Steel 100 (12.2L, ~2,830L gas) – more gas, better for deeper or longer dives; AL63 (8.9L) – lighter, suitable for smaller divers or shorter shallow dives. Choose based on your SAC rate, planned depth, and desired dive duration. Steel tanks are often preferred for their buoyancy characteristics and higher capacity.
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