Grams to Moles Calculator – Plus Convert Moles to Grams

Convert grams to moles and moles to grams using our g to mol conversion calculator below.

grams
moles

Quantity:

  moles

Molar Mass

  g/mol


How to Convert Grams to Moles

Grams and moles are both units used to measure matter in different ways. Grams are an SI unit of mass equal to 1/1,000 of a kilogram[1], and the mole is the SI base unit to measure the quantity of substance.[2]

One mole is equal to 6.02214076 × 1023 elementary units of matter, such as atoms or molecules. Because that’s such a large number, it’s almost always represented using scientific notation.

At this point, you might be wondering how to convert grams, which are a measure of mass to moles, which are a measure of the quantity of substance. Because every substance is composed of different atomic elements, the atomic mass of each element within needs to be accounted for to determine the molar mass.

Molar mass, represented in g/mol, will be needed along with the formula below to convert. You can use a molar mass calculator for that calculation if you don’t have it handy. The calculator above even calculates this for you.

Grams to Moles Formula

As we just mentioned, you’ll need to g to mol formula to convert grams to moles using the molar mass of the substance. The g to mol formula is:

n = mM

Thus, the quantity of substance n in moles is equal to the mass m in grams divided by the molar mass M in g/mol.

graphic showing the grams to moles formula stating that the quantity in moles is equal to the mass in grams divided by the molar mass in g/mol

The formula above is actually derived from the molar mass formula:

M = mn

The molar mass formula states that the molar mass M is equal to the mass of substance m divided by the quantity n.[3]

For example, let’s calculate the quantity of 30 grams of nitrogen (N2) in moles. Note that the molar mass of nitrogen is 28.0134 g/mol.

n = 3028.0134
n = 1.0709 mol

So, in this example, the quantity of 30 grams of nitrogen is 1.0709 moles.

Did you know you can also convert liters and atoms to moles as well?

How to Convert Moles to Grams

To convert the quantity of substance in moles back to the mass in grams, we simply need to reverse the formula above.

Moles to Grams Formula

The formula can be rewritten to convert moles to grams like this:

m = n × M

Thus the mass of substance m in grams is equal to the quantity n in moles multiplied by the molar mass M in g/mol.

For example, let’s calculate the mass of 2 moles of carbon dioxide (CO2). The molar mass of carbon dioxide is 44.0095 g/mol.

m = 2 × 44.0095
m = 88.019 g

So, the mass of 2 moles of carbon dioxide is 88.019 grams.

You can also use our mole calculator to find the quantity of a substance.

References

  1. National Institute of Standards and Technology, SI Units - Mass, https://www.nist.gov/pml/weights-and-measures/si-units-mass
  2. International Bureau of Weights and Measures, SI base unit: mole (mol), https://www.bipm.org/en/si-base-units/mole
  3. National Institute of Standards and Technology, NIST Guide to the SI, Chapter 8, https://www.nist.gov/pml/special-publication-811/nist-guide-si-chapter-8