Molality Calculator (m)
Calculate Molality, Solute Mass, or Solvent Mass (Temperature Independent)
(1 kg Water ≈ 1000 mL)
Result:
0.00 m
Instructions:
Molality is moles solute / kg solvent.
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How to Use the Molality Calculator
Molality (m) is a measure of the concentration of a solute in a solution in terms of amount of substance in a specified amount of mass of the solvent. Unlike Molarity (M), Molality is independent of temperature because it is based on mass rather than volume.
Step 1: Select Your Goal
Choose what you need to calculate from the dropdown menu:
- Molality (m): If you know the mass of solute and solvent.
- Mass of Solute: If you need to prepare a specific molal solution.
- Mass of Solvent: If you need to know how much solvent to add.
Step 2: Enter Molecular Weight
Input the Molecular Weight (MW) of your solute in g/mol. For example, Glucose is approx 180.16 g/mol, NaCl is 58.44 g/mol.
Step 3: Input Values & Calculate
Enter the known values (Mass in grams or kg) and click Calculate. The result will appear instantly below, along with a printable GMP-compliant report section.
Key Formula
m = (masssolute / MW) / masssolvent(kg)