sentences:  Note that this is different from 50% volume fraction (expressed as a percentage); the latter does not take into account change in volume on mixing, whereas the former does.To make 50% ABV from pure alcohol, one would take 50 parts of alcohol and dilute to 100 parts of solution with water, all the while mixing the solution.To make 50% alcohol by volume fraction, one would take 50 parts alcohol and 50 parts water, measured separately, and then mix them together.