# Relative Density vs. Specific Gravity: What's the Difference?

Edited by Huma Saeed || By Sawaira Riaz || Published on January 2, 2024
Relative density is the ratio of the density of a substance to a reference substance, while specific gravity is the ratio of the density of a substance to that of water at 4°C.

## Key Differences

Relative density measures how dense a substance is compared to another reference substance, often water. Specific gravity is a special case of relative density, where the reference substance is always water at its densest state (4°C).
Sawaira Riaz
Jan 02, 2024
In the context of relative density, the reference substance can vary depending on the application. However, for specific gravity, the reference point is universally water at 4°C, making it a more standardized measure.
Sawaira Riaz
Jan 02, 2024
Relative density is dimensionless, as it's a ratio of densities. Similarly, specific gravity is also dimensionless, as it compares the density of a substance to that of water.
Sawaira Riaz
Jan 02, 2024
Relative density can be used for solids, liquids, or gases, with the reference substance changing accordingly. In contrast, specific gravity is typically used for liquids and solids, with water being the constant reference.
Aimie Carlson
Jan 02, 2024
In calculations, relative density can be adjusted for temperature and pressure variances. Specific gravity, while also affected by temperature and pressure, is generally referenced at a standard condition (water at 4°C).
Harlon Moss
Jan 02, 2024

## Comparison Chart

### Spelling

"Relative density" has 16 letters.
"Specific gravity" has 16 letters.
Sawaira Riaz
Jan 02, 2024

### Pronunciation

Pronounced as /ˌrɛləˈtɪv ˈdɛnsɪti/.
Pronounced as /spəˈsɪfɪk ˈɡrævɪti/.
Sawaira Riaz
Jan 02, 2024

### Syllables

Five syllables: Re-la-tive-den-si-ty.
Five syllables: Spe-ci-fic-grav-i-ty.
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Jan 02, 2024

Used as a noun.
Used as a noun.
Sawaira Riaz
Jan 02, 2024

### Usage in a Sentence

"The relative density of iron is higher than wood."
"The specific gravity of mercury is quite high."
Aimie Carlson
Jan 02, 2024

## Relative Density and Specific Gravity Definitions

#### Relative Density

A quantity without any units.
Relative density is a dimensionless value.
Sawaira Riaz
Dec 20, 2023

#### Specific Gravity

A property used to identify substances.
Specific gravity aids in substance identification.
Janet White
Dec 20, 2023

#### Relative Density

A measure for comparing densities of two substances.
Relative density helps in understanding buoyancy.
Sawaira Riaz
Dec 20, 2023

#### Specific Gravity

A standard measure in scientific studies.
Specific gravity is used in geology for rock classification.
Harlon Moss
Dec 20, 2023

#### Relative Density

A property of materials comparing to a standard.
The relative density of aluminum is less than steel.
Janet White
Dec 20, 2023

#### Specific Gravity

Reflects how dense a material is compared to water.
Specific gravity varies widely among minerals.
Sawaira Riaz
Dec 20, 2023

#### Relative Density

A concept used in physics to understand substance behavior.
Relative density affects fluid dynamics.
Aimie Carlson
Dec 20, 2023

#### Specific Gravity

Comparison of a substance's density to that of water.
Specific gravity determines if an object will float.
Sawaira Riaz
Dec 20, 2023

#### Relative Density

The ratio of the density of a substance to that of a reference substance.
Relative density is crucial in material selection.
Sawaira Riaz
Dec 20, 2023

#### Specific Gravity

A unitless measure in fluid mechanics.
Specific gravity is key in hydrometer readings.
Sawaira Riaz
Dec 20, 2023

## FAQs

#### How are relative density and specific gravity related?

Specific gravity is a type of relative density with water as the reference.
Sawaira Riaz
Jan 02, 2024

#### Is specific gravity always measured against water?

Yes, it's always compared to water at 4°C.
Sawaira Riaz
Jan 02, 2024

#### What is relative density?

Relative density is the ratio of the density of a substance to that of a reference substance.
Sawaira Riaz
Jan 02, 2024

#### What is specific gravity?

Specific gravity is the ratio of the density of a substance to that of water at 4°C.
Sawaira Riaz
Jan 02, 2024

#### How does specific gravity affect buoyancy?

It determines whether a substance will float or sink in water.
Harlon Moss
Jan 02, 2024

#### Can gases have a relative density?

Yes, when compared to a reference gas.
Janet White
Jan 02, 2024

#### Why use relative density?

Relative density helps compare materials and understand their properties.
Aimie Carlson
Jan 02, 2024

#### What role does specific gravity play in industries?

It's crucial in fields like geology, chemistry, and material science.
Harlon Moss
Jan 02, 2024

#### Can relative density have units?

No, relative density is a dimensionless quantity.
Sawaira Riaz
Jan 02, 2024

#### Is specific gravity used in the food industry?

Yes, for liquids like milk and juices.
Sawaira Riaz
Jan 02, 2024

#### Does temperature affect relative density?

Yes, temperature can change the density of the reference and the substance.
Sawaira Riaz
Jan 02, 2024

#### Can relative density be more than 1?

Yes, if a substance is denser than the reference.
Sawaira Riaz
Jan 02, 2024

#### Is relative density used in geology?

Yes, for comparing mineral densities.
Aimie Carlson
Jan 02, 2024

#### What's the specific gravity of water?

By definition, it's 1 at 4°C.
Janet White
Jan 02, 2024

#### Does pressure affect relative density?

It can, especially for gases.
Janet White
Jan 02, 2024

#### Can specific gravity be used in medical diagnostics?

Yes, in analyzing urine and other bodily fluids.
Janet White
Jan 02, 2024

#### Do relative density and specific gravity have practical applications?

Absolutely, in engineering, science, and everyday life.
Janet White
Jan 02, 2024

#### Why is specific gravity important in fluid mechanics?

It helps in understanding fluid behavior and properties.
Harlon Moss
Jan 02, 2024

#### How do you measure specific gravity?

Using a hydrometer or a density meter.
Janet White
Jan 02, 2024

#### What's an example of a high relative density?

Metals like gold and platinum have high relative densities.
Janet White
Jan 02, 2024