What is Molarity?
The Molarity Calculator computes the concentration of a solution in moles per liter (M). Molarity is the most common way to express solution concentration in chemistry and is essential for lab work, stoichiometry, dilutions, and titrations.
Molarity (M) = moles of solute / liters of solution. For example, dissolving 58.44 grams of NaCl (1 mole) in enough water to make 1 liter of solution gives a 1 M NaCl solution.
This calculator is indispensable for students preparing solutions in chemistry labs, researchers in biology and biochemistry, pharmacists calculating drug concentrations, and anyone working with chemical solutions.
Common molarities: household vinegar ~0.8M acetic acid, stomach acid ~0.1M HCl, seawater ~0.6M NaCl.
Formula
Molarity (M) = Moles / Volume (L) Moles = Mass (g) / Molar Mass (g/mol)
Combined: M = Mass / (Molar Mass × Volume)
Example — 58.44g NaCl in 1L: Moles = 58.44 / 58.44 = 1 mol Molarity = 1 / 1 = 1 M
Example — 4g NaOH (MW=40) in 500mL: Moles = 4 / 40 = 0.1 mol Molarity = 0.1 / 0.5 = 0.2 M
How to use this Molarity Calculator?
1. Enter mass of solute in grams. 2. Enter the molar mass (molecular weight) in g/mol. Look this up on the periodic table or use: NaCl=58.44, NaOH=40, H₂SO₄=98, HCl=36.46, glucose=180.16. 3. Enter the total volume of solution in liters. 4. See moles, molarity, and mg/mL concentration.