Difference Between Density and Specific Gravity

There is a noticeable difference between density and specific gravity even though both are used to represent mass and are used to compare different substances. Density is the property of matter represented by a ratio of mass to a unit volume of matter. Specific gravity which is also called as relative density is a measure of density with respect to a density of pure water. There are many properties of water such as conductivity of water and many more.

Difference Between Density and Specific Gravity

Difference Between Specific Gravity and Density

If a material has a specific gravity less than 1, it will float on water. Specific gravity is also called relative density.

It is represented as,

\(specific\; gravity_{substance}=\rho _{substance}/\rho _{reference}\)

Density on the other hand is represented as ,

\(\rho = mass/volume\)

And it is represented in kilograms per cubic meter

Difference Between Density and Specific Gravity


Specific Gravity (Relative Density)

It is mass of an object per unit volume

Relative density is the ratio of a substance’s weight to the weight of 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 substance with density of water.

It is represented in absolute term

It is represented in relative term

Its symbol is P is represented in kilogram per cubic meter

It does not have a SI unit

It is used in many domestic and commercial applications

It is used in industries to measure the concentration of solutions.

These were some difference between specific gravity (relative density) and density. If you wish to find out more, download BYJU’S The Learning App.


Practise This Question

A cylinder is rotating with angular velocity ω and angular acceleration α at any instant, while translating with velocity V. Find the net acceleration of point P at this instant (radius of cylinder is R).