Molarity Calculator

Calculate the mass, volume or molarity of a solution using the calculator below.

g/mol
g/mol
g/mol

Molarity:

 
M


How to Calculate Molarity

Molarity is the amount or concentration of a substance in a volume of solution. Molarity is also known as the molar concentration of a solution and is denoted with the letter M.

Molarity is the ratio of the amount of solute in moles to the volume of solution in liters. Molarity differs from molality in that it is a ratio of the amount of substance to volume, while molality is a ratio of the amount of substance to mass.

Molarity Formula

You can find molarity using a widely accepted formula.

molar concentration (mol/L) = mass (g) ÷ molar mass (g/mol) ÷ volume (L)

The molarity is just the mass in grams divided by the molar mass in g/mol divided by the volume in liters. This formula can be simplified into the following standard equation, which is most commonly referenced when calculating molarity.

M = nv

Thus, the molarity M of a solution is equal to the amount of solute n in moles divided by the volume of substance v in liters.

The amount of substance in moles can be found using the molar mass of the formula and the mass of substance. Use our molar mass calculator if you need to calculate the molecular weight of the solute.

n = mM

The amount of substance n in moles is equal to the mass of substance m in grams divided by the molar mass M.

Of course, you can also use our mole calculator to find the amount of substance.

How to Calculate Mass

To find the mass of a solution, we can use a different formula.

mass (g) = molar concentration (mol/L) × volume (L) × molar mass (g/mol)

The mass in grams of a solution is equal to the molar concentration in molars times the volume in liters times the molar mass of the substance in g/mol.

How to Calculate Volume

Similarly, to find the volume of a solution, we also use a formula.

volume (L) = mass (g) ÷ molar mass (g/mol) ÷ molar concentration (mol/L)

The volume in liters of a solution is equal to the mass in grams divided by the molar mass of the substance in g/mol, divided by the molar concentration in molars.