Molecular Weight Calculator
Adds standard atomic masses for a supported set of elements in simple chemical formulas such as H2O and CO2.
How it works
Simple formula molar mass
Formula and assumptions
Molar mass is the sum of each element’s atomic mass multiplied by its subscript. This version supports simple formulas without parentheses, hydrate notation or nested groups; unsupported elements are rejected.
Example
Use the sample values, calculate, and change one input at a time.
Frequently asked questions
Are results exact? Results depend on the assumptions and inputs above.
Can I use this for professional decisions? Verify critical results independently.
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Frequently asked questions
Are parentheses supported in formulas?
No. This version accepts simple formulas made from the listed elements and numeric subscripts, without grouped parentheses.
What should I check before relying on the result?
Confirm the input units and assumptions described above; independently verify safety-critical, medical, financial or professional decisions.
How is molar mass calculated?
Molar mass is the sum of each element’s atomic mass multiplied by its subscript in the chemical formula.
Does this calculator support parentheses or hydrate notation?
This version supports simple chemical formulas without parentheses, hydrate notation or nested groups. Use the syntax described on the calculator page.