Calculators / Partial pressure and mixes

Gas mixing calculator

How much of each of two gases to put in to reach a final pressure and oxygen percentage.

Mixing two gases

A = final x (final% - B%)/(A% - B%)

METRIC

Final pressure (bar)Final O2 %Gas A O2 %Gas B O2 %

The formula: A = final x (final% - B%)/(A% - B%). Change any box and the full working updates. For study only, never for dive planning.

Practise it the way the exam asks it

The IMCA ADS, BDS and LST papers ask this as a four-option question, with a calculator on screen. A free account gives you 15 practice questions for each exam, each with the worked answer and the document it comes from.

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