How to Convert Density to a Specific Gravity

The density of a substance measures how much substance is in a given volume. The formula for density is mass divided by volume (density = mass/volume). Specific gravity is a ratio of the density of a substance to the density of a reference substance, usually water. Since the density of water is one gram per cubic centimeter, specific gravity is calculated by dividing the density of a substance by one gram per cubic centimeter. Since a number divided by one is itself, the specific gravity of a substance is the density absent the units of measure.

Things You'll Need

• Pencil
• Paper

Instructions

1. Determine the density of a substance. This may be done by dividing the mass by the volume of the substance or more directly through the use of instruments such as a hydrometer.

2. Divide the density of the substance by the density of water. Water has a density of one gram per cubic centimeter (1 g/cm3).

3. The quotient is the specific gravity of the substance.

References

• University of Oregon Physics Department: What are Density and Specific Gravity
• Georgia State University: Mass, Weight, Density
• New York University: Density