Molarity Calculator
Moles, mass and concentration for any solution.
Enter your values
Enter the mass of solute in g.
Enter the molecular weight in g/mol.
Enter the solution volume in L.
Results update instantly as you type — no submit needed. Your values are remembered on this device, and the shareable link reopens the calculator with exactly these numbers.
- Molarity
- 1 mol/L
- Moles of solute
- 1 mol
- Millimolar
- 1000 mM
- Mass percent (aqueous, approx)
- 5.844%
Working
- 1moles = 58.44 ÷ 58.44 = 1
- 2M = 1 ÷ 1 = 1
Quick answer
Molarity is moles of solute per litre of solution: M = mass ÷ (molar mass × litres).
M = mass ÷ (MW × V)
At a glance
| What it does | Moles, mass and concentration for any solution. |
|---|---|
| Category | Science |
| Inputs needed | Mass of solute, Molecular weight, Solution volume |
| Main output | Molarity |
| Formula | M = mass ÷ (MW × V) |
| Cost | Free — no sign-up, no download |
How to use the Molarity Calculator
- 1Enter the mass of solute in grams.
- 2Add the molecular weight.
- 3Enter the final solution volume in litres.
Inputs explained
- Mass of solute(g)
- Enter the mass of solute in g.
- Molecular weight(g/mol)
- Enter the molecular weight in g/mol.
- Solution volume(L)
- Enter the solution volume in L.
Worked example
Using the values the calculator loads with:
Inputs
- Mass of solute58.44 g
- Molecular weight58.44 g/mol
- Solution volume1 L
Results
- Molarity1 mol/L
- Moles of solute1 mol
- Millimolar1000 mM
- Mass percent (aqueous, approx)5.844%
- moles = 58.44 ÷ 58.44 = 1
- M = 1 ÷ 1 = 1
Frequently asked questions
Molarity vs molality?
Molarity uses litres of solution and changes with temperature; molality uses kilograms of solvent and does not.
How do I dilute a stock solution?
Use M₁V₁ = M₂V₂ — multiply the stock concentration by the volume taken and divide by the final volume.
What do I need to enter into the Molarity Calculator?
Just 3 values: mass of solute, molecular weight, solution volume. Every field starts with a realistic example, so you can change one number at a time and watch the result update instantly.
How does the Molarity Calculator work out the answer?
Molarity is moles of solute per litre of solution: M = mass ÷ (molar mass × litres). It applies the formula M = mass ÷ (MW × V) and shows the working so you can check each step by hand.
Is the Molarity Calculator free, and do I need an account?
It is completely free with no sign-up, no download and no usage limit. Everything is calculated in your browser, so the numbers you type never leave your device.
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.