MolCalc is a sophisticated stylish molecular weight calculator. Enter a chemical formula using the clickable periodic system or the iPhone keyboard and MolCalc displays the molecular weight as well as the percentage of each element and the number of atoms.

Use brackets to enter more complicated formulas and see MolCalc count out the number of atoms correctly.

The results screen is not erased after each calculation but keeps all previous results during the active session. You can scroll back and compare different molecules all in one screen. You can even email the results screen to keep a record of your calculations.

Atomic weights are stored and used internally with as many digits as is currently available according to the IUPAC 2007 values. Output is rounded to the third decimal place.