Enter the chemical formula of a compound to calculate its molar mass and elemental composition:
Tip: Chemical formula is case sensitive. C10H16N2O2c10h16n2o2
Instructions to calculate molar mass (molecular weight) of a chemical compound:
To calculate molar mass of a chemical compound, please enter its chemical formula and click 'Calculate'.
Definitions of molecular mass, molecular weight, molar mass and molar weight:
Molecular mass (molecular weight) is the mass of one molecule of a substance and is expressed in the unified atomic mass units (u). (1 u is equal to 1/12 the mass of one atom of carbon-12) Molar mass (molar weight) is the mass of one mole of a substance and is expressed in g/mol.
Pro Tip: Free Base vs. Salt Forms
Check Your Vial Label! This calculator determines the theoretical molecular weight based on the chemical formula you provide. However, many small molecule inhibitors are supplied as salt forms (e.g., HCl, TFA, or Tosylate salts) or solvates to improve stability and solubility.
Theoretical MW: Calculated from the pure chemical structure (e.g., Free Base).
Batch-Specific MW:The actual molecular weight of the substance in your vial, including any counter-ions or water molecules.
Result:
Note: When preparing stock solutions for biological assays, always use the Batch-Specific Molecular Weight found on the specific vial label or the Certificate of Analysis (CoA).
Molecular Weight vs. Molar Mass
While often used interchangeably in the laboratory, these terms have distinct scientific definitions:
Molecular Weight (MW): The mass of a single molecule, measured in unified atomic mass units (amu or Da). It is the sum of the atomic weights of all atoms in the molecule.
Molar Mass (molar weight): The mass of one mole (6.022*1023 particles) of a substance, expressed in grams per mole (g/mol). For practical laboratory calculations, the numerical value is effectively the same as the Molecular Weight.
See Also:
Molarity Calculator : Determine the mass needed to create your initial stock solution.
Dilution Calculator : Calculate how to dilute your stock solution to a working concentration.
