To convert 390 ml to grams, besides the volume we have to know the substance’s density ρ in g/cm3 or in any other unit. Alternatively, when we know the material, then we can look for its density in a search engine. As explained on our home page, 390 ml equal 390 cm3, and as also outlined there, in common use the equation for water is 390 milliliter = 390 g
