DiverInterCom KCore Scuba · Dive Calculators

Calculator Fun Playground

A place for quick, visual, educational dive estimates. Calculator No. 1 is a starting-weight estimator that combines water type, body size, exposure protection and an approximate cylinder buoyancy effect.

Fun estimate · always verify in water

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1. Weight Calculator

Enter the diver and equipment configuration. The result is an estimated starting point in kilograms.

Estimated Starting Weight

Lead/ballast estimate only. The three views make the cylinder effect visible.

Diver alone

—kg

—

With full tank

—kg

—

With tank at 50 bar

—kg

—

Estimated tank buoyancy · full—

Estimated tank buoyancy · 50 bar—

Exposure / water estimate—

Body-profile adjustment—

Water-density adjustment—

How this playground estimate works: it starts with a rough percentage of body weight for the selected exposure protection, makes a small body-profile correction using height/weight, then applies an approximate cylinder buoyancy correction. The 50-bar result is the most useful of the three as an end-of-dive weighting reference.

Why the result is a range: two divers with the same height and weight can need different ballast because body composition, suit brand/age, BC, plate, regulators, cylinder model, salinity and trapped gas all matter. The centre number is a starting estimate, not a target to trust blindly.

2. Real SAC / RMV Calculator

Use a real dive to calculate your surface-equivalent gas consumption.

Tank size (L)

Start pressure (bar)

End pressure (bar)

Average depth (m)

Dive time (min)

Calculated SAC / RMV

—L/min

Gas used

—L

Enter a real dive to see how cylinder gas use becomes a surface-equivalent breathing rate.

3. Tank Gas Calculator

Tank size × pressure = nominal available gas at surface pressure.

Tank size (L)

Pressure (bar)

Available gas

—L

A cylinder marked 11.1 L at 200 bar contains about 2,220 L of nominal gas at surface pressure.

4. RMV at Depth

Surface SAC/RMV × ambient pressure = approximate gas use per minute at depth.

SAC / RMV (L/min)

Depth (m)

RMV at depth

—L/min

At 30 m the ambient pressure is about 4 bar, so gas use is about four times the surface SAC.

5. Available Time at Depth

Uses tank size, pressure, reserve, SAC/RMV and constant depth. Descent, ascent and stop gas are not subtracted.

Tank size (L)

Pressure (bar)

Reserve (bar)

SAC / RMV (L/min)

Depth (m)

Available time at depth

—min

This is a constant-depth gas-duration estimate only.

6. Simple NDL Calculator

Select a gas and depth. Output is limited to estimated NDL, MOD at PPO₂ 1.4 bar, and PPO₂ at depth.

Gas

Depth (m)

Model

O₂ %

N₂ %

He %

Estimated NDL

—min

MOD · PPO₂ 1.4

—m

PPO₂ at depth

—bar

Single square-dive estimate from fresh surface-saturated tissues. Descent is modeled at 18 m/min and direct ascent at 9 m/min. Repetitive diving, gradient-factor conservatism, CNS/OTU, altitude, gas density and individual factors are not included. Pure oxygen has no inert-gas NDL in this model; oxygen exposure becomes the limiting factor.

7. Best Mix Calculator

Choose a planned depth and PPO₂ limit. The result is the highest oxygen fraction that reaches that PPO₂ at depth.

Depth (m)

Target PPO₂ (bar)

Maximum O₂ fraction

—%

At 30 m, PPO₂ 1.4 corresponds to about 35% oxygen.

8. Equivalent Air Depth (EAD)

For Nitrox only: compare the nitrogen exposure of a Nitrox dive with an equivalent depth on air.

O₂ fraction (%)

Actual depth (m)

Equivalent air depth

—m

EAN32 at 30 m gives roughly the same nitrogen partial pressure as air at about 24 m.

9. Trimix & Gas Physics

Enter any O₂ / N₂ / He mix and depth to see its partial pressures, equivalent narcotic depth and approximate gas density.

O₂ %

N₂ %

He %

Depth (m)

END model

PPO₂

—bar

PPN₂

—bar

PPHe

—bar

END

—m

Gas density

—g/L

Partial pressure is gas fraction × ambient pressure. END is shown using the selected narcotic-gas convention. Gas density is an approximate ideal-gas comparison; 5.2 g/L and 6.2 g/L are shown as useful reference points, not sharp physiological boundaries.

Calculator Fun Playground: intentionally compact educational calculators. For full gas management, staged ascents and decompression planning, use the dedicated DiverInterCom tools and trained procedures.

Always perform an in-water weight check and verify dive plans independently. These playground calculators are educational estimates and cannot account for all real-world conditions or implementation differences.