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Molarity Calculator

Calculate solution molarity from moles or mass, molar mass, and volume.

Need to dilute this solution? Dilution Calculator →

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What is molarity?
Molar concentration (symbol M) is the number of moles of solute dissolved per litre of solution. Unit: mol/L (M).
Formulas
From moles: M = n / V  ·  From mass: M = mass / (molar mass × V)
Worked example — 0.1 M NaCl
5.844 g NaCl (Mw = 58.44 g/mol) dissolved in 1 L of water gives 0.1 mol/L = 0.1 M. The same concentration in 500 mL requires 2.922 g.
Molarity vs molality
Molarity (mol/L) depends on solution volume, which changes with temperature. Molality (mol/kg solvent) does not — prefer it when temperature varies.
Need the molar mass?
Use the Molecular Weight Calculator to compute Mw from a chemical formula.
Need to dilute this solution?
Use the Dilution Calculator to solve C₁V₁ = C₂V₂ for any unknown.