Molarity Calculator
Find the molar concentration of a solution from the amount of solute (in moles or grams) and the total solution volume.
Solute input
g
g/mol
Volume unit
Moles of solute per liter of solution
- 1
Moles = mass ÷ molar mass
58.44 ÷ 58.44 = 1 - 2
Volume in litres
1 - 3
Molarity = moles ÷ volume (L)
1 ÷ 1 = 1Volume is that of the final solution, not the solvent alone.
How does this calculator work?
Molarity equals moles of solute divided by liters of solution. If you only know the mass, convert to moles by dividing by the molar mass first, then divide by the volume in liters. Enter milliliters and the calculator converts them automatically, returning the concentration in mol/L.
Formula
How this is calculated
Molarity expresses concentration as the number of moles of solute dissolved per liter of solution. The core relationship is M = n / V, where n is moles of solute and V is the solution volume in liters.
If you supply the solute as a mass instead of moles, the calculator first converts to moles using n = mass / molar mass. Molar mass is the sum of the atomic masses of every atom in the formula (for example, NaCl is 22.99 + 35.45 = 58.44 g/mol). Volume entered in milliliters is converted to liters by dividing by 1000 before the division.
The volume used is that of the final solution, not the solvent alone, and a stable temperature is assumed since liquid volume changes slightly with temperature. Volume and molar mass must be positive; a zero or negative volume or molar mass returns no result.
Frequently asked questions
Molarity (mol/L) is moles of solute per liter of solution, while molality (mol/kg) is moles of solute per kilogram of solvent. Molality is independent of temperature because it uses mass, whereas molarity changes slightly as volume expands or contracts with temperature.
Add up the atomic masses of all atoms in the chemical formula. For example, glucose (C6H12O6) is 6×12.01 + 12×1.008 + 6×16.00 = 180.16 g/mol.
Always use the total volume of the final solution. Dissolving a solute can change the overall volume, so measuring after mixing gives the correct molarity.
Also known as
TG we-Calculate Editorial Team. (2026). Molarity Calculator [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/molarity-calculator
TG we-Calculate Editorial Team. "Molarity Calculator." TG we-Calculate. 2026. https://we-calculate.com/calculator/molarity-calculator.
TG we-Calculate Editorial Team, "Molarity Calculator," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/molarity-calculator
@misc{wecalculate_molarity_calculator, title = {Molarity Calculator}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/molarity-calculator}}, year = {2026}, note = {TG we-Calculate} }
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