Molar Mass of Gas

If you want to determine the number of moles present in gas and its molar mass, you can use our molar mass of gas calculator.

Molar mass, also known as molecular weight, is a mass of a single particle of a gas multiplied by Avogadro's number equivalent to 6.02 x 1023. In mathematical form, A substance of gas having 1 mol of mass, also narrated as grams per mole equivalent to the atom's/molecule's mass of 6.022 × 1023, is known as the Molar Mass of Gas.

To find out the molar mass of any gas, you must know the value of the mole, or to find the value of the mole, you must know the data listed below:

  1. Pressure

  2. Temperature

  3. Gas Volume

After having the above data, you can determine the moles' value by using the ideal gas law.


Formula of Molar Mass of Gas Calculator

To find the value of moles, you can use the modified ideal gas law formula listed below:

Moles = (Pressure * Volume) / (0.0821 * Temperature)

Whereas The SI units used in the above values are listed below:

  • Volume is equal to Liters (L).

  • Temperature is equal to Kelvin (K).

  • The pressure is equal to the Atmosphere (atm).

Moreover, 0.0821 is a constant value designed for the above data. You can now calculate the molar mass of any gas substance by using our molar mass of gas calculator or using the formula listed below:

Molar mass = Mass / Moles

Mass is the weight of the gas, and the SI unit used for it is grams (g).


To convert PPM to molarity, you can use our PPM To Molarity Calculator.


If gas has 5.709 moles and the total weight or mass of a gas is 14g, then find out the molar mass of the gas.

To solve the problem narrated above, we will use the formula of molar mass.

Given data

Moles in gas = 5.709 mol
Mass of a gas = 14g

To Find

The molar mass of gas = ?


By using the formula listed below, we will find the molar mass of gas:

Molar mass = Mass / Moles

Putting values in the formula:

Molar mass = 14 / 5.709 = 2.4523 g/mol

How to use the Molar Mass Of Gas Calculator?

The steps to use the molar mass of gas calculator are as follows:

Step 1: Enter the value of pressure in the first required input.

Step 2: Enter the value of temperature in the second required input.

Step 3: Enter the value of volume in the third required input.

Step 4: Enter the value of mass in the third required input.

Step 5: The calculator will automatically display an answer on the screen.

Calculator use

To find out the molecular weight of any gas, you can use our molar mass of gas calculator. Enter the required value, and the solution will appear on the screen.