Molarity Calculator
Calculate the molar concentration of a solution from the solute's mass, its molar mass and the solution volume.
Molarity
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Moles of solute —
In mmol/L —
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How it works
Molarity M = (mass ÷ molar mass) ÷ volume in litersFrequently Asked Questions
How do I calculate molarity?
Convert mass to moles (divide by molar mass), then divide by liters of solution: 58.44 g of NaCl (molar mass 58.44 g/mol) in 0.5 L is 2.0 M.
Where do I find molar mass?
Sum the atomic masses from the periodic table: NaCl = 22.99 + 35.45 = 58.44 g/mol; glucose C₆H₁₂O₆ = 180.16 g/mol; H₂SO₄ = 98.08 g/mol.
How do I dilute to a target molarity?
Use M₁V₁ = M₂V₂: to make 250 mL of 0.5 M from a 2.0 M stock, you need V₁ = (0.5 × 250)/2.0 = 62.5 mL of stock topped up to 250 mL.