Empirical Formula Calculator

Convert element amounts to mole ratios, scale them toward small whole-number subscripts, and show when the fit is uncertain.

Use masses or percentages consistently. Atomic weights are taken from the bundled periodic-table data.

—Whole-number ratios are not forced when the data fit is poor.

How to use this Empirical Formula Calculator

Find an empirical formula from element masses or percent composition. Enter your values above and the result is calculated directly in your browser. No account is required.

Fast answer, clear inputs

This tool is built around one job: give the answer quickly without forcing a signup or hiding the result. Related tools are linked nearby when the next calculation or conversion is useful.