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Science & Engineering

Molarity Calculator

Calculate molarity from solute mass, molar mass and solution volume, or the mass needed for a target concentration.

Your inputs

NaCl ≈ 58.44 g/mol.

Results

Molarity

0.2 mol/L

Moles of solute
0.1 mol
In millimolar
200 mM

✓Exact calculation — rounded only for display

What this calculator does

Molarity (mol/L) is the most common concentration unit in chemistry labs.

Formula and method

moles = mass ÷ molar mass; M = moles ÷ volume (L); mass needed = M × V × molar mass

Worked example

Calculated by this tool with its default inputs:

Inputs

  • Calculate: Molarity from mass and volume
  • Molar mass of the solute: 58.44 g/mol
  • Mass of solute: 5.844 g
  • Final solution volume: 0.5 L

Results

  • Molarity: 0.2 mol/L
  • Moles of solute: 0.1 mol
  • In millimolar: 200 mM

How to read the results

1 M NaCl contains about 58.44 g per litre of solution.

Assumptions and limitations

  • Volume is of the final solution, not the solvent.

These are educational estimates. Electrical, structural and other safety-critical work must comply with local codes and be designed or checked by a qualified professional.

Questions

Molarity vs molality?

Molality is moles per kilogram of solvent; it does not change with temperature.

Methodology and verification

Result type
Exact mathematical calculation (rounded only for display)
Formula version
1.0
Automated verification
3 reference and validation test cases, checked against independently computed values. The site cannot be built if any of them fail.
Editorial review
Awaiting human editorial review. The explanation was drafted with AI assistance; the formula and examples are verified by the automated tests above.

Privacy

Everything you enter is calculated in this browser and is not sent to Numerith or anyone else. Inputs are added to a share link only if you choose to include them. Privacy policy