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Solution amount

Molarity to moles calculator

If a solution’s molarity and final volume are known, multiply mol per liter by liters of solution to get the moles of solute in that portion.

Enter your values

Result

Results are based only on the inputs and assumptions shown here. Nothing you enter is sent or saved.

Formula: moles of solute = molarity (mol/L) × final solution volume (mL) ÷ 1,000

Worked example

A 0.25 mol/L solution portion of 500 mL contains 0.25 × 0.5 = 0.125 mol, or 125 mmol, of the named solute.

The volume is solution volume

OpenStax defines molarity as moles of solute per liter of solution. Enter the final or sampled solution volume, not the amount of solvent used before dissolving a solute. The calculation does not assume any substance identity.

When mass is the starting point

A mass in grams cannot become moles without a molar mass. The main grams-to-moles calculator uses a formula or known molar mass for that separate task. Here, the molarity already contains the amount-per-volume information.

Units and limitations

The calculator divides mL by 1,000 before multiplying, and shows mmol and µmol as alternate units. Accuracy depends on the molarity and volume supplied. Zero concentration or zero volume yields zero moles; nothing is stored or sent.

Explore the related calculation

For a different starting point, try the molarity from solute mass or return to the main calculator. Browse the complete tool directory for this site.

Reference and corrections

The definitions and assumptions above follow these sources; the examples and calculator arithmetic are original to this page.

Found a problem? Email contact@gramstomoles.org.