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Molarity calculator

Compute the molar concentration of a solution from moles and volume.

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Enter Moles (mol), Volume (L) and the Molarity calculator works out Molarity (mol/L) straight away. For instance, with Moles (mol) = 0.5 and Volume (L) = 2 it returns Molarity (mol/L) = 0.25.

How to use it

  1. Enter your values: Moles (mol), Volume (L).
  2. Read the result instantly: Molarity (mol/L).

Frequently asked questions

How does the Molarity calculator work?

It takes Moles (mol) and Volume (L) and derives Molarity (mol/L) from them. The calculation is live as you type, so the result updates on every change.

Which values does the calculator ask for?

2 values: Moles (mol) and Volume (L). Nothing else is required — no account, no file upload.

What does a typical calculation look like?

With Moles (mol) = 0.5 and Volume (L) = 2, the calculator returns Molarity (mol/L) = 0.25. Those figures come from running this exact tool, so you can reproduce them by entering the same values.

How much does the result change with different inputs?

It moves a lot. Using Moles (mol) = 1 and Volume (L) = 2.2 instead, Molarity (mol/L) goes from 0.25 to 0.455 — which is why it is worth testing a few scenarios rather than trusting a single figure.

What does it give for smaller values?

Scaled down to Moles (mol) = 0.25 and Volume (L) = 1.8, Molarity (mol/L) comes out at 0.139. The relationship is worth checking at both ends before you rely on a single result.

When would I actually use this?

Preparing a solution at a stated concentration, working out how much of a reagent a reaction needs, and converting between mass, moles and volume.

What is the most common mistake?

Confusing molarity with molality. One is per litre of solution and the other per kilogram of solvent; they diverge as concentration rises, and only one of them is temperature-independent.

What is the difference between the Molarity calculator and the Ideal gas law calculator?

This one returns Molarity (mol/L); the Ideal gas law calculator returns Pressure (atm). That is the whole difference — open the one whose figure you need.

Is there a tool for the next step?

Normality calculator is the closest one after this: Compute the normality of a solution — gram-equivalents of solute per litre. Enter equivalents directly or a mass with its molar mass and n-factor, plus the volume, and it returns the normality (N) and the equivalent molarity (M = N ÷ n-factor).

What else is worth having open alongside it?

Titration calculator and Dilution calculator (C1V1 = C2V2) — they come up in the same task often enough to be worth a second tab.

Further reading

All guides →
How-toHow to Calculate a Dilution with C1V1 = C2V2Solve for the missing term, then convert the answer into a bench instruction. The step almost everyone skips is that the solvent you add is V2 minus V1, not V2.How-toHow to Calculate pH — And When the Weak-Acid Shortcut Stops WorkingFour routes for four kinds of solution, each worked with real numbers. Including the part most pages leave out: the square-root formula for a weak acid is an approximation with a validity limit, and it fails quietly.ExplainerThe Ideal Gas Law Explained: PV = nRT, R in Every Unit, and Where It BreaksPV = nRT holds when the gas is dilute and far from condensing. The value of R depends entirely on the units you feed it, and the temperature is never in degrees Celsius.How-toHow to Calculate Molar Mass, Including Parentheses and HydratesMultiply each atomic weight by its subscript and add. The only three places the arithmetic goes wrong are a subscript after a closing bracket, the hydrate dot, and a capital letter typed as a lowercase one.ExplainerHow Half-Life Works: What Is Left After 1, 3 and 10 Half-LivesOne half-life leaves 50%, three leave 12.5%, ten leave less than a tenth of a percent. The formula is a single line — the part worth understanding is why the answer never reaches zero.How-toHow to Solve Stoichiometry Problems: Grams to Moles to Ratio to GramsEvery problem in the chapter is the same four moves. The mole ratio is the hinge, and it is the step students lose — worked here end to end, limiting reactant and percent yield included.