The formula to calculate molarity is to divide the moles of solute dissolved in the solution by volume of solution in liters. Molarity is a concentration unit that measures the number of moles of a solute for each liter of solution.

To find the number of moles in the solute, convert the weight of the solute into moles using the atomic masses of the elements in the solute. Add up the atomic masses of the elements to find the weight of one mole. Divine the weight of the solute by the weight of one mole to find the number of moles in the solute. Convert the weight of the solution to liters if necessary.