Molarity calculator for concentration, moles and solution volume
Choose concentration, moles or final solution volume as the unknown. HitEquals solves c=n/V, converts concentration and volume units, and provides dilution-style comparison rows.
Inputs used by this calculator
Molarity Calculator uses the fields below. The starting values reproduce the page example; replace them with values from the same units and time period before using the result.
| Input | Starting example | Accepted value | How it is used |
|---|---|---|---|
| Solve for | Amount concentration | Amount concentration · Amount of substance · Solution volume | Chooses which Molarity Calculator method or unknown the engine evaluates. |
| Concentration | 0.5 | 0 to 1000000000000 | Supplies the concentration quantity used by the published equation or result breakdown. |
| Concentration unit | mol/L | mol/L · mmol/L · mol/m³ | Selects the unit or conversion path used by Molarity Calculator. |
| Amount of substance (mol) | 0.25 | 0 to 1000000000000 | Supplies the amount of substance (mol) quantity used by the published equation or result breakdown. |
| Solution volume | 0.5 | 0 to 1000000000000 | Supplies the solution volume quantity used by the published equation or result breakdown. |
| Volume unit | Liters | Liters · Milliliters · Cubic meters | Selects the unit or conversion path used by Molarity Calculator. |
What molarity means
The common term molarity refers to amount-of-substance concentration: the amount of a specified solute divided by final solution volume. NIST prefers the unambiguous quantity name.
Core concentration formulas
All three modes rearrange one definition.
c=n/Vn=cVV=n/cWorked 0.5 mol/L example
Dividing 0.25 mol by 0.5 L gives 0.5 mol/L, which is also 500 mol/m³ or 500 mmol/L.
Final solution volume matters
If solute is added to solvent, the denominator is the final mixed volume. It is not automatically the starting solvent volume.
Molarity versus molality
Amount concentration divides by solution volume; molality divides solute amount by solvent mass. They are different quantities and need density to interconvert.
Laboratory limitations
Real preparation must account for purity, reaction stoichiometry, temperature-dependent volume, calibrated glassware and safety requirements.
Concentration-unit relationships
| Entered unit | Equivalent |
|---|---|
| 1 mol/L | 1,000 mol/m³ |
| 1 mmol/L | 1 mol/m³ |
| 1 mol/m³ | 0.001 mol/L |
| 1 L | 0.001 m³ |
Frequently asked questions
What is molarity?
The commonly used name for amount of solute divided by final solution volume.
What formula does it use?
c=n/V.
Is molarity the same as molality?
No; molality uses solvent mass.
Should I use solvent volume?
Use final solution volume.
How many mol/m³ are in 1 mol/L?
One thousand.
Does this calculate chemical reactions?
No; reaction stoichiometry is outside this page.
What to keep in mind
The result uses final solution volume, not solvent volume before mixing. Temperature, reaction, purity, activity, dissociation and volume change are outside this arithmetic model.
Results are rounded for display in US format, with money in dollars and cents; CSV exports keep full calculation precision. This is a calculation summary, not an official certificate.