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Molarity Calculator
Compute molar concentration from moles of solute and volume of solution.
Formula
M = moles / litres
How to use
- 1Enter the moles of solute.
- 2Enter the total solution volume in litres.
- 3Read the molarity in moles per litre.
About this calculator
Concentration answers a simple question: how much of something is dissolved in how much liquid? In chemistry the standard answer is molarity, the moles of a dissolved substance per litre of solution. This calculator computes it directly from the moles of solute and the volume of solution.
Formula explained
M (mol/L) = moles ÷ litres. Rearranged, moles = M × volume and volume = moles ÷ M. Use the volume of the finished solution, not the solvent you started with - dissolve the solute, then top up to the target volume.
Worked example
0.5 mol ÷ 1 L = 0.5 M. Halve the volume to 0.5 L and the same 0.5 mol gives 1 M - less liquid, higher concentration.
Tips & notes
- Convert any mass to moles first using the correct molar mass.
- Keep volume in litres; divide millilitres by 1000.
- For dilutions, moles stay constant, so C1 × V1 = C2 × V2.