How to Calculate Molecular Weight
Calculate exact molar mass step-by-step:
Enter Formula
Input case-sensitive chemical formula (e.g. C8H10N4O2).
Parse Element Counts
System parses atom counts for every element and polyatomic group.
Multiply Atomic Weights
Multiply IUPAC standard atomic weight of each element by its count.
Sum Total Mass
Sum all subtotals to get total molecular weight in g/mol or Daltons (Da).
Key Features & High Precision
Parentheses & Hydrate Parsing
Parses nested groups like Fe2(SO4)3 and hydrated salts cleanly.
IUPAC Atomic Mass Database
Includes high-precision standard atomic mass constants for all elements.
Total Atom Tally
Calculates total number of atoms in one single formula unit.
General Chemistry Guide: Molecular Weight (MW)
Molecular Weight (MW), also called molar mass or formula weight, is the sum of the atomic masses of all atoms present in a chemical formula. It represents the mass in grams of one mole ($6.022 \times 10^23$ molecules) of that substance.
Frequently Asked Questions
?What is the difference between g/mol and Daltons (Da)?
g/mol and Daltons (Da) are numerically identical. 1 g/mol = 1 Dalton (1 amu per individual molecule).