# Difference Between Density and Specific Gravity

There is an obvious difference between density and specific gravity, although both are used to represent weight and compare different objects. Density is something that represents the ratio of weight to unit mass of an object.

Specific gravity, also called relative density, is a measure of density relative to the density of pure water. Water has many properties, such as hydraulic conductivity and many others.

### What is the Definition of Density?

Density is a property of matter which can be alternatively defined as the ratio of mass to unit mass of matter. It is usually expressed in grams per cubic centimeter or kilograms per cubic meter.

Mass per unit volume used for its calculation. Density, therefore, is a measure of how compact a substance or object is. It is a scalar quantity for its direction. Its measurement is a method of determining the mass in a continuous cycle.

### What is the Definition of Specific Gravity?

It is a measure of density compared to the density of a standard reference material. In most cases, the reference is pure water. An object with a specific gravity less than one can also float in water.

The specific gravity of a material can be calculated using a simple ratio between the density of the ideal material and the density of the liquid.

### Difference Between Density and Specific Gravity

Density |
Specific Gravity (Relative Density) |

It is the mass of an object per unit volume. | Relative density is the ratio of a substance’s weight to the weight of the same volume of water. |

To calculate density, we need to know the weight and volume of the substance. | We can get this by dividing the density of a substance with the density of water. |

It is represented in absolute terms. | It is represented in relative terms. |

Its symbol is ρ is represented in kilogram per cubic metre. | It does not have an SI unit. |

It is used in many domestic and commercial applications. | It is used in industries to measure the concentration of solutions. |