The result of your conversion between gram/cubic kilometer and grain/cubic foot appears here
To convert between Gram/cubic Kilometer and Grain/cubic Foot you have to do the following:
First divide 0.001/1.0E+9 / ((0.45359237/16)*(192/175)/480)/((0.0037854118/231)*1728) = 0.
Then multiply the amount of Gram/cubic Kilometer you want to convert to Grain/cubic Foot, use the chart below to guide you.
Symbol: g/km³
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Symbol: gr/ft³
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