Converts a density into kg/m³, g/cm³, lb/ft³ and more. Water is exactly 1 g/cm³, which is 1000 kg/m³ or 62.4 lb/ft³. Since g/cm³, kg/L and t/m³ all mean the same thing, they appear here as one entry.
This converts a density between kg/m³, g/cm³, lb/ft³, lb/in³, oz/in³ and lb/gal.
Multiplying the top by a thousand multiplies the bottom by a thousand too, so all three name the same value. The table carries g/cm³ alone as their representative. Water comes to exactly 1 in these units, which is why a figure in g/cm³ doubles as a specific gravity.
Water at 1 g/cm³ is 1000 kg/m³, 62.428 lb/ft³ and 8.345 lb/gal. Iron at 7.85 g/cm³ is 7850 kg/m³ and 490.06 lb/ft³. The figure 62.4 lb/ft³ turns up constantly in American sources, and knowing it is water gives a sense of scale.
Specific gravity is the ratio to the density of water, a number with no units. It is not a density, but it shares its value with the density expressed in g/cm³. A recipe saying soy sauce has a specific gravity of 1.2 means 1.2 g/cm³.
The gallon in lb/gal is the US liquid gallon of 3.785411784 L. The imperial gallon of 4.54609 L shifts the figure by about a fifth.