Skip to content
LunaCalc

Chemistry

Molarity Calculator

Calculate molarity, moles of solute and solution volume.

Calculator

About this calculator

This molarity calculator relates moles of solute, solution volume, and molar concentration, solving whichever one is missing.

Formula notes

M = n / V, with n in moles and V in liters. Rearranged: n = M·V and V = n / M.

Worked examples

  1. Example: 0.5 mol of NaCl in 0.25 L of solution is 0.5 / 0.25 = 2 M.
  2. Dissolving 0.250 mol of solute to a final solution volume of 0.500 L gives a molarity of 0.500 mol/L.

How to use it

  1. Enter any two of moles, volume, and molarity.
  2. Make sure the volume is in liters.
  3. Read the missing third quantity.

Frequently asked questions

Is molarity based on solvent or solution volume?

Solution volume — the total after mixing, not just the solvent you started with.

How do I prepare a 1 M solution?

Dissolve 1 mole of solute and add solvent until the total volume reaches 1 L.

Limits and interpretation

  • Use final solution volume, not merely the volume of solvent added before dissolution.
  • Volume changes with temperature and non-ideal mixing; high-precision laboratory work needs calibrated volumetric equipment.

References