Molecular Weight of Compounds
Look up the molecular weight of common chemical compounds instantly. This reference tool provides molecular weights for organic molecules, inorganic salts, acids, bases, pharmaceuticals, and biochemical compounds. Enter any formula or click an example compound to see its molecular weight with a complete element breakdown and percentage composition.
Geben Sie oben eine Formel ein, um das Molekulargewicht zu berechnen
Quick Molecular Weight Reference
Type a formula to look up its molecular weight instantly.
Finding the molecular weight of a compound is one of the most common tasks in chemistry. Whether you're preparing solutions, calculating yields, or checking reagent specifications, you need the molecular weight.
This tool provides instant molecular weight lookup for any compound you can write as a chemical formula. The values match those published in PubChem, the CRC Handbook of Chemistry and Physics, Sigma-Aldrich catalogs, and the Merck Index.
Common compounds like aspirin (180.16 g/mol), caffeine (194.19 g/mol), and cholesterol (386.65 g/mol) are immediately available. For any compound not listed, simply type its molecular formula.
Atomic Weights Behind Compound Masses
Every compound molecular weight traces back to the atomic weights of its elements.
The molecular weight of any compound is the sum of the atomic weights of all its constituent atoms. Light elements like hydrogen (1.008) contribute little individually, while heavy elements like gold (196.97) or lead (207.20) contribute substantially.
Organic compounds (containing C, H, O, N, S) generally range from 16 g/mol (methane) to over 1000 g/mol (complex biomolecules). Inorganic compounds span an even wider range depending on the metals involved.
Explore the atomic weights below — these are the building blocks of every compound molecular weight.
How to Look Up Compound Molecular Weight
Find, view, and save molecular weights in 3 steps.
Find the Compound
Identify the compound you need and locate its chemical formula from a textbook, database, or product label. Common compound formulas are listed below — click any to load it instantly. For compounds not listed, type the molecular formula directly.
Molecular Weight Reference Table
Click any compound to load it and see the full molecular weight breakdown.
Molecular Weight of Compounds FAQ
Questions about finding and using compound molecular weights.