Can I enter formulas with parentheses like Ca(OH)2?

Not currently. The parser only reads flat element-and-count sequences such as CaOH2 written out fully; nested groups in parentheses are not expanded, so you should manually multiply out the atoms inside brackets before entering the formula.

Where do the atomic weights come from?

The calculator sums each element's standard atomic weight (as published by IUPAC, rounded to typical periodic-table precision) multiplied by how many times that element appears in the formula, giving the result in grams per mole.

Molecular Weight Calculator

Calculate the molecular weight of a chemical compound from its formula.

How this is calculated

Molecular weight = Σ (atomic weight × atom count) for each element

Assumptions used in this calculation

Formula format: Supports flat formulas with element symbols and counts (e.g. C6H12O6); nested parentheses like Ca(OH)2 are not supported.

About this calculator

The molecular weight calculator parses a chemical formula and sums the atomic weights of its constituent elements to find the total molecular weight.

Worked example

Water (H2O)

Result: 18.015 g/mol

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Frequently asked questions

Molarity Calculator

Solve for molarity, mass or volume of a solution.

Molecular Weight Calculator

About this calculator

Frequently asked questions

Can I enter formulas with parentheses like Ca(OH)2?

Where do the atomic weights come from?

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