Insert the information in the form and the calculator will determine the atomic weight.

What is the atomic weight?

The atomic weight is the average mass of atoms of an element. In other words the atomic weight is the weighted average of the masses of naturally-occurring isotopes.

How to calculate atomic weight?

To calculate atomic weight you should use the following formula:
atomic weight = (mass1 * (fract1 / 100)) + (mass2 * (fract2 / 100))

Why use atomic weight?

The atomic weight is used to find the average mass of molecules and elements and also to solve stochiometry problems.