Chemistry Calculator
Get molar mass with a full element breakdown and percent composition, then convert grams, moles, molecules and molarity. Handles nested brackets and hydrates, with IUPAC-accurate atomic weights.
Element breakdown & percent composition
Your digital lab assistant
Smart parser
Nested brackets like Fe2(SO4)3, organics like CH3COOH, and hydrates like CuSO4.5H2O all parse correctly.
Full breakdown
Not just the total. See each element's atom count, mass contribution and percent composition instantly.
IUPAC accurate
Current standard atomic weights, e.g. chlorine at 35.45, for analytical-grade precision.
The complete chemistry calculator
This chemistry calculator does more than a molar mass lookup. Type any formula and it returns the total molar mass, a per-element breakdown, and the percent composition by mass, then lets you convert between grams, moles, molecules and molarity in the second tab. Every atomic weight is hardcoded to current IUPAC standards for lab-grade accuracy.
How to enter a formula
- Case matters: capitalise the first letter, lowercase the second. Use
NaCl, notnacl, so the tool tells Co (cobalt) from CO (carbon monoxide). - Subscripts are numbers: write
H2Ofor two hydrogens. A missing number means one. - Groups use brackets: polyatomic ions like ammonium sulfate go in as
(NH4)2SO4. - Hydrates use a dot: enter copper(II) sulfate pentahydrate as
CuSO4.5H2O(a dot or an asterisk both work).
Compound weight quick reference
| Compound | Formula | g/mol |
|---|---|---|
| Water | H2O | 18.015 |
| Glucose | C6H12O6 | 180.156 |
| Sulfuric acid | H2SO4 | 98.079 |
| Ammonium sulfate | (NH4)2SO4 | 132.14 |
| Ethanol | C2H5OH | 46.068 |
From grams to molarity
Moles = mass / molar mass. Molecules = moles × Avogadro's number (6.022 × 10²³). Molarity = moles / volume in litres. The Moles & molarity tab does all three at once, so you go from a weighed sample straight to a solution concentration.
Frequently asked questions
Molar mass vs molecular weight?
Why does 'na' or 'NACL' fail?
Can it calculate molarity?
Does it handle hydrates?
CuSO4.5H2O. The parser adds the water molecules to the total.