Intrepid Underwater
Dive Calculators
Gas planning tools for SAC/RMV, tank fills, trimix costs, and reserve checks — built for the way you actually plan a dive.
⚠ FOR INFORMATIONAL PURPOSES ONLY. These calculators are not a substitute for proper dive training. Always rely on certified instruction, your dive agency's standards, and your dive computer before making gas or decompression decisions.
SAC / RMV Calculator Consumption
Calculates surface air consumption (SAC) and respiratory minute volume (RMV) from a dive's starting/ending pressure, elapsed time, and average depth.
Dive Data
Tank
PSI Used
0psiSAC Rate
0psi/minSAC / RMV
0cuft/minGas Consumption Calculator Consumption
Uses your RMV plus an intended depth and time to estimate how much gas a planned segment of the dive will consume.
Plan Inputs
Gas Consumed
0cuftShearwater SAC Converter Consumption
Converts a SAC rate reported by a Shearwater dive computer (psi/min) into RMV in cuft/min, using your tank's rated volume and pressure.
Back Gas
Deco Gas
Back Gas RMV
0cuft/minDeco Gas RMV
0cuft/minGas Consumption Estimator Consumption
Estimates PSI consumption and ending pressure for back gas (BG) and deco gas (DG) tanks based on expected volume consumption.
Back Gas (BG)
Deco Gas (DG)
BG · PSI Used / Ending PSI
0psi0psi end
DG · PSI Used / Ending PSI
0psi0psi end
Tank Fill Volume Calculator Tank & Fill
Calculates the fill volume of a tank from its rated pressure, rated volume, and actual fill pressure — corrected for gas compressibility using the Z-factor.
Tank 1
Tank 2
Tank 1 · Fill Volume
0cuftTank 1 · True Gas Volume
0cuftTank 2 · Fill Volume
0cuftTank 2 · True Gas Volume
0cuftTrue Gas Volume applies the Z-factor to account for real-gas compressibility at high fill pressures — it will typically read lower than the ideal-gas fill volume.
Volume Consumption Calculator Tank & Fill
Compares a tank's starting and ending pressure against its rated volume and pressure to show how much gas (in cuft) was consumed and what percentage of the available gas that represents.
Tank A
Tank B
Tank A · Consumed
0cuftTank A · % of Gas Used
0%Tank B · Consumed
0cuftTank B · % of Gas Used
0%Tank Final Pressure Estimator Tank & Fill
Takes an estimated volume of gas consumed along with starting pressure, rated pressure, and rated volume to estimate the tank's final pressure at the end of the dive.
Expected
Actual
Expected Ending Pressure
0psiActual Ending Pressure
0psiAscent Rate Calculator Dive Profile
Calculates ascent rate in feet per minute from a starting and ending time and depth.
Start
End
Ascent Rate
0ft/minTarget ascent rates are typically 30 ft/min or slower — check your agency standards and computer guidance.
Trimix Price Calculator Trimix
Uses tank volume, tank rated pressure, and the amount of pre-blend trimix used to estimate the volume and cost of a fill, based on the selected pre-blend price.
Tank
Pre-Blend Fill
CuFt of Pre-Blend
0cuftFill Price
0$Back Gas Reserve Checker Reserve
Compares your tank's fill and rated numbers against estimated consumption to show remaining reserve capacity on back gas.
Tank 1
Tank 2
Tank 1 · Real Volume
0cuftTank 1 · Reserve
0%Tank 2 · Real Volume
0cuftTank 2 · Reserve
0%Deco Gas Reserve Checker Reserve
Same reserve-capacity comparison as the back gas checker, sized for deco bottles. Labels update automatically to match the tank volume you enter or select.
Tank 1
Tank 2
Tank 1 · Real Volume
0cuftTank 1 · Reserve
0%Tank 2 · Real Volume
0cuftTank 2 · Reserve
0%Gas Weight Calculator Trimix
Calculates the weight of gas in a fill based on the mix of helium, oxygen, and nitrogen present.
Mix
Gas Constants (lb/cuft)
% N2
0fractionHe Weight
0lbO2 Weight
0lbN2 Weight
0lbTotal Weight
0lb