Rex says
The fast lane for the math you almost remember from school. Type the numbers, get the answer, move on with your day.
Try a scenario
Click to load — tweak from there.Inputs
Result
Molarity (mol/L)
1.0000
Moles of solute
1.0000
Millimolar (mM)
1000.00
Concentration (g/L)
58.440
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter solute mass (g).
- 2Enter molar mass (g/mol).
- 3Enter solution volume (L).
- 4Read your molarity (mol/l) on the right — it updates as you type.
- 5Hit Share to keep the scenario or send it to someone.
About this calculator
Molarity is moles of solute per litre of solution. Enter mass, molar mass, and volume to get concentration — plus how much you'd need for a target molarity.
Worked example
Using the values the calculator loads with:
Inputs
- Solute mass: 58.44 g
- Molar mass: 58.44 g/mol
- Solution volume: 1 L
Results
- Molarity (mol/L): 1
- Moles of solute: 1
- Millimolar (mM): 1,000
- Concentration (g/L): 58.44
What each field means
Inputs
- Solute mass (g)
- The solute mass used in the calculation, measured in g. Starts at 58.44 g so you have a working example on load.
- Molar mass (g/mol)
- The molar mass used in the calculation, measured in g/mol. Starts at 58.44 g/mol so you have a working example on load.
- Solution volume (L)
- The solution volume used in the calculation, measured in L. Starts at 1 L so you have a working example on load.
Results
- Molarity (mol/L)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Moles of solute
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Millimolar (mM)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Concentration (g/L)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the molarity (solution concentration) calculator work?
Molarity is moles of solute per litre of solution. Enter mass, molar mass, and volume to get concentration — plus how much you'd need for a target molarity. The underlying maths is: M = (mass ÷ molar mass) ÷ litres
What do I need to enter?
3 values: solute mass, molar mass, and solution volume. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the molarity (mol/l) result mean?
It is returned as a decimal number and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are rounded for display; the underlying calculation keeps full precision.
Who is this tool for?
It's built for students, developers, and anyone who needs the answer right now without setting up a spreadsheet.
Accuracy and limitations
- Results are rounded for display; the underlying calculation keeps full precision.
- Very large or very small inputs may hit floating-point limits in the browser.
- Inputs outside the accepted range are clamped rather than rejected.
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). Molarity Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/molarity
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/molarity" target="_blank" rel="noopener">Molarity Calculator — RevenueLab</a> (2026).</p>
Source: [Molarity Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/molarity) (2026).