Concentration Calculator
Concentration Calculator works out Molarity and Moles of solute from Moles of solute, Solute mass and Molar mass of the solute. The default figures on this page give molarity of 0.500000 mol/L; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
1 step
- M = n / V = 2 mol / 4 L = 0.5 mol/L
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the Concentration Calculator calculates
Relates molarity, moles of solute, solute mass, molar mass and solution volume, solving for whichever of them the supplied values determine.
How to use this Concentration Calculator
Enter Moles of solute, Solute mass, Molar mass of the solute and Final solution volume. Molarity updates as you type. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Molarity, Moles of solute and Solute mass.
The method follows OpenStax Chemistry 2e, section 3.3 Molarity, OpenStax Chemistry 2e, section 3.1 Formula Mass and the Mole Concept and IUPAC Compendium of Chemical Terminology (Gold Book), "amount concentration" and "mass concentration".
What you can compare
Change one input at a time to see how it affects Molarity, Moles of solute and Solute mass. The inputs you can vary are Moles of solute, Solute mass, Molar mass of the solute, Final solution volume and Target molarity.
Understanding Molarity, Moles of solute and Solute mass
Solution preparation figures assume the final volume is made up to the stated value. Confirm reagent purity, hydration state and the molar mass you entered before weighing anything out.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
How do I calculate concentration?
Relates molarity, moles of solute, solute mass, molar mass and solution volume, solving for whichever of them the supplied values determine. Open “How this is worked out” beside the result to see each step for your own figures.
What is 1% concentration in mg/mL?
Relates molarity, moles of solute, solute mass, molar mass and solution volume, solving for whichever of them the supplied values determine. On this page it is computed from Moles of solute, Solute mass and Molar mass of the solute and shown as Molarity, Moles of solute and Solute mass.
How do I convert concentration to molarity?
It needs Moles of solute, Solute mass, Molar mass of the solute, Final solution volume and Target molarity. Nothing else is required, and the figures stay in your browser.
What information do I need for the Concentration Calculator?
You need Moles of solute, Solute mass, Molar mass of the solute, Final solution volume and Target molarity. The page opens with default figures that give molarity of 0.500000 mol/L, so you can see the scale before entering your own.
What does this Concentration Calculator show?
It shows Molarity, Moles of solute, Solute mass, Mass concentration, Solution volume and Millimolar equivalent, with the working and any warnings for your entries.
Can I check how the Concentration Calculator result was calculated?
Yes. The “How this is worked out” section shows the calculation steps, and the sources section identifies the references used for the method.