Enter any three of the four variables — Mass of Solute, Molecular Weight, Solution Volume, and Molarity (Concentration) — and the Molarity Calculator solves for the missing one, also giving you the Number of Moles, Required Mass, and Required Volume across your choice of mass, volume, and concentration units.
Molarity
--
Required Mass
--
Required Volume
--
Number of Moles
--
Molarity (M) is a measure of concentration expressed as moles of solute per liter of solution. It's calculated using the formula: M = n/V, where n is the number of moles and V is the volume in liters.
Molecular weight (or formula weight) is the sum of atomic weights of all atoms in a chemical formula, expressed in g/mol. It's essential for converting between mass and moles in molarity calculations.
Use the formula: Mass (g) = Molarity (M) × Volume (L) × Molecular Weight (g/mol). This tells you exactly how much solute to weigh out for your desired concentration.
Calculate the required total volume using: Volume (L) = Mass (g) ÷ (Molarity (M) × Molecular Weight (g/mol)). The solvent volume will be slightly less than this total volume.
Yes! First convert mass to moles by dividing by molecular weight, then divide moles by volume in liters: M = (Mass ÷ MW) ÷ Volume.
The calculator supports various units: mass (kg to ng), volume (L to nL), concentration (M to fM), and molecular weight (g/mol or kg/mol). All conversions are handled automatically.
Molarity calculations are highly accurate when molecular weights and measurements are precise. However, consider factors like solution temperature and density for critical applications.