What is a Molarity Calculator?

The Molarity Calculator is a free, simple tool which calculates the molarity (M) of a solution (ratio of moles of solute per liter of solution (mol/L)). This can help with many areas of homework, lab prep and research when you require fast, precise results derived from grams, moles, molar mass, and volume—without doing the calculations manually.

How Does the Molarity Calculator Work?

1. Provide the solute amount, which can be either mass (g) or moles (mol);
2. Provide the molar mass (g/mol); this is a required item if mass is provided; it is optional if the input is in moles.
3. Provide the volume of the solution in L or mL (the tool automatically converts mL → L: 1000 mL = 1 L);
4. Click the Calculate button, and the Molarity (M) is immediately calculated.

Do you need to dilute a stock? If so, under the M1V1 = M2V2 section, provide any three values, and solve for the fourth (ensuring both gallons are provided in the same unit).

Molarity Calculator Formula

• Molarity: M = n / V
  (where n = moles of solute, V = solution volume in liters).
• From grams: n = mass (g) / molar mass (g/mol)
  then M = n / V.
• Dilution: M₁V₁ = M₂V₂
  (volumes in the same unit; V is total solution volume, not solvent added).

Key Benefits of Using This Molarity Calculator Online

• Speed and accuracy - protect yourself from manual errors in concentration math.
• Flexible input - work with grams or moles, and with either L or mL.
• Embedded dilution - solve M₁V₁ = M₂V₂ for rapid stock preparation.
• Lab-realistic - excellent for recipe sheets, titration calculations, or getting ready to make buffers.
• Device-ready - optimized functions for both mobile and desktop, for use while working at the bench.

Disclaimer

This Molarity Calculator is for educational and informational use only. Results are based on standard formulas and may include rounding. Always verify concentrations, units, and dilutions against your lab protocols and safety documents (e.g., SDS) and consult a qualified supervisor for critical work.