Specific Gravity Calculator

Specific gravity calculator determines the relative density of various materials in relation to water. It helps to understand how dense or light a substance is compared to water, which is often used as a reference point.

What Is Specific Gravity?

“Specific gravity is the ratio of a substance’s density relative to the density of the standard substance”

Under standard conditions, solids and liquids are often compared with water at 4°C which has a density of 1,000 grams per liter. When assessing gases, it is evaluated by comparing to the dry air which has a density of 1.29 grams per liter (1.29 ounces per cubic foot)

What Is The Formula For Specific Gravity?

The specific gravity is typically calculated by using the below formula:

\(SG = \frac{\text{Density of Substance}}{\text{Density of Reference Substance}}\)

\(SG =\frac{\rho_{\text {substance }}}{\rho_{\text {reference }}}\)

The reference density of water at 4ºC (39ºF) at which water reaches its maximum density. Specific gravity for liquids and solids is typically assessed relative to water at 4ºC (39.2ºF).

How Do I Calculate Specific Gravity?

To calculate the specific gravity of a substance divide the density of material by the density of water or air.

Example:

Assume that in the laboratory with a density of 2,700 kg/m³, there is a sample of aluminum. Find the specific gravity of aluminum where the water density is 1000 kg/m³.

Solution:

Given Values:

• Material density (ρ_material) = 2700 kg/m³
• Water density (ρ_water) = 1000 kg/m³

Calculate Specific Gravity (SG):

The specific gravity formula calculates the relationship between a reference material’s density and the density of a substance.

SG = ρ material / ρ water

= 2700 / 1000

= 2.7

The specific gravity of aluminum is determined to be 2.7 and this indicates that the material is 2.7 times denser than the volume of water.

Is Specific Gravity Affected By Temperature?

Yes, the specific gravity is affected by the temperature and also by the pressure. As the temperature increases then the substance density decreases which in turn affects the specific gravity. The objects have a specific gravity of 1 and are in equilibrium with water.

Specific Gravity Table For Different Materials: