Molarity Calculator
Calculate molarity, moles of solute, or volume of solution using M = n/V.
Results
What is it?
Molarity (M) measures the concentration of a solute in a solution as moles of solute per litre of solution: M = n/V. It is the most widely used concentration unit in chemistry, biology, and pharmacy. Note: molarity (mol/L) differs from molality (mol/kg of solvent) ā molality does not change with temperature, while molarity does.
How to use
Select the variable you want to solve for, then enter the other two known values. Switch between Molarity, Moles, and Volume modes freely.
Example scenario
You dissolve 0.5 mol of NaCl into 1 litre of water. Select "Molarity", enter moles = 0.5 and volume = 1 L. The result is 0.5 mol/L ā a 0.5 M saline solution (physiological saline is ~0.154 M).
Pro tip
Dilution shortcut: when diluting a solution, the moles of solute stay constant, so CāVā = CāVā. For example, to prepare 500 mL of 0.1 M HCl from a 1 M stock: Vā = (0.1 Ć 0.5) / 1 = 0.05 L = 50 mL of stock, then top up to 500 mL with distilled water.