Molarity Calculator
Calculate molarity in mol/L and millimolar concentration from solute amount and solution volume.
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Guide
How this molarity calculator works
This tool calculates molarity by converting solute amount to moles, converting solution volume to liters, then dividing moles by liters.
Enter solute amount
Use moles, millimoles, or grams. If you choose grams, add the molar mass so the tool can convert grams to moles.
Enter solution volume
Use liters or milliliters for the final solution volume, not just the added solvent.
Read concentration
Molarity is shown in mol/L, with millimolar concentration shown as molarity multiplied by 1,000.
FAQs
What is molarity?
Molarity is concentration measured as moles of solute per liter of solution.
How do you calculate molarity?
Convert the solute to moles, convert the solution volume to liters, then divide moles by liters.
When do I need molar mass?
Molar mass is needed when the solute amount is entered in grams because grams must be converted to moles first.
What is the difference between molarity and millimolar?
Millimolar, or mM, is one-thousandth of a molar. To convert mol/L to mM, multiply by 1,000.
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