Molality Calculator
Find the molality of a solution (moles of solute per kilogram of solvent) by entering the solute mass, its molar mass, and the mass of the solvent.
What Is Molality?
Molality (m) measures the concentration of a solution as the number of moles of solute dissolved per kilogram of solvent. Unlike molarity, molality does not depend on temperature because it is based on mass rather than solution volume, which makes it useful for precise laboratory work such as freezing-point depression and boiling-point elevation calculations.
The Formula
Molality is calculated as: molality (mol/kg) = moles of solute ÷ kilograms of solvent. Moles of solute are found by dividing the solute’s mass by its molar mass. This calculator performs both steps for you.
- Enter the mass of the solute in grams.
- Enter the solute’s molar mass in grams per mole.
- Enter the mass of the solvent in kilograms.
This tool is intended for general chemistry education and lab planning purposes; always confirm critical results against your course materials or a calibrated lab reference.