How to use the Molarity Calculator
The molarity calculator finds a solution's concentration in moles per litre.
Open the Molarity Calculator →
What you need to enter
- Mass of solute (g)
- Molar mass (g/mol)
- Volume of solution (L)
The formula
Molarity = (mass ÷ molar mass) ÷ volume in litres.
Worked example
Using the default values in the calculator:
- Mass of solute (g): 5.85
- Molar mass (g/mol): 58.44
- Volume of solution (L): 0.5
| Molarity | 0.200205 mol/L |
| Moles | 0.100103 mol |
| Millimolar | 200.2053 mM |
Tips for better results
- Use the molar mass from a periodic table.
- Volume is of the solution, not the solvent.
Common mistakes to avoid
- Using millilitres.
- Wrong molar mass.
Please note: Results are estimates for general use. For safety-critical work such as electrical or building projects, check with a qualified professional and local codes. See our Disclaimer.