# Specific Gas Constant Calculator

The specific gas constant calculator estimates the value of the specific gas constant using **two different methods**. You can calculate the specific gas constant for the gas/mixture either using the **molar mass of gas** or using the **specific heat capacity** for the gas mixture. Read on to understand the process to calculate the specific gas constant. The value of specific gas constant comes in handy in a wide range of applications such as **compressible fluids, compressors, pipelines, and aerodynamics**.

## What is the specific gas constant?

The specific gas constant is defined as the ratio of molar gas constant to the molar mass of the gas and is measured in the units, `J/kg∙K`

. The ideal gas law formula establishes the relation between the properties of the gas such that:

`P * V = n * R * T`

,`P`

is pressure, `V`

is [volume](calc:866), `n`

is number of [moles](calc:1400), `T`

is [temperature](calc:206), and `R`

universal gas constant.
The specific gas constant `R`_{s}

varies per different gases and mixtures. It can be written mathematically as:
`R`_{s} = R / M

,`M`

is the molar mass of the gas or mixture.
Alternatively, the specific gas constant also relates the two specific heat capacities for the mixture or gas. The specific gas constant for constant pressure `C`

and for constant volume _{p}`C`

can be related as:_{v}

`R`_{s} = C_{p} - C_{v}

## How to calculate specific gas constant?

Follow the steps below to calculate the specific gas constant.

- Step 1: Select the method to calculate specific gas constant.
- Step 2A: If you picked the
**molar mass**method, enter the molar mass of the gas. - Step 3A: The calculator will return the value of specific gas constant.

Alternatively:

- Step 2B: If you picked the
**specific heat**method, enter the specific heat capacity at constant pressure. - Step 3B: Enter the specific heat capacity at constant volume.
- Step 4: The calculator will return the value of specific gas constant.

## Example: Using the specific gas constant calculator.

Estimate the specific gas constant of air. Take molar mass as `28.96 g/mol`

.

- Step 1: Pick
**molar mass**method from the list. - Step 2: Enter the molar mass of the gas.
- Step 3: The calculator will return the value of specific gas constant of air as:

`R`_{s} = R / M = 8.314 / 0.02896 = 287.058 J/kg∙K

## Specific gas constant for common gases

## FAQ

### How do you find the specific gas constant?

To calculate the specific gas constant: **Divide the universal gas constant by the molar mass of gas.**

### How are specific gas constant and specific heat related?

The specific gas constant and specific heats of gases are related as: `R`

._{s} = C_{p} - C_{v}

### What is the specific gas constant for oxygen?

The specific gas constant for oxygen is `259.84 J/kg∙K`

. It is calculated using its molar mass `31.99 g/mol`

and universal gas constant: `8.314 / 0.03199 = 259.84 J/kg∙K`

.

### What is the specific gas constant for steam?

The specific gas constant for steam is `461 J/kg∙K`

. It is calculated using its molar mass `18.01 g/mol`

and universal gas constant: `8.314/0.018 = 461 J/kg∙K`

.