Method
Molar mass = Σ(element atomic weight × subscript count). Element symbols are case-sensitive.
Everyday worksheet
Molecular Weight Calculator
Parse a simple chemical formula and sum standard atomic weights with a per-element contribution audit.
The calculation runs locally. Results include the intermediate values, unit conversions and assumptions needed to audit the answer.
Method, assumptions and practical use
How the Molecular Weight Calculator works
Molar mass = Σ(element atomic weight × subscript count). Element symbols are case-sensitive. Inputs stay in this browser, and the result table exposes conversions and assumptions for independent checking.
Interpret the result
The numerical molar mass in g/mol is also the relative molecular mass value on the unified atomic-mass scale.
Check the assumptions
Atomic weights are conventional averages and can vary by isotopic composition; this parser supports a limited element set and simple formulas only.
Local calculation
Everything runs in this browser. Inputs are not sent to an external calculator.
Rounding
Displayed values may be rounded for readability while calculations use full floating-point precision unless the tool explicitly uses exact integers.
Scope
Atomic weights are conventional averages and can vary by isotopic composition; this parser supports a limited element set and simple formulas only.
Simple by design
Three steps to a clearer number.
Enter your details
Use realistic values in each field. You can change them anytime.
Calculate instantly
The formula runs locally, so there is no account or waiting time.
Use the result
Treat the answer as a practical estimate for your next decision.