What this calculator does
Empirical formula from mass percent works out simplest whole-number atom ratio of a compound from percent composition and atomic masses. Enter your own figures above and the answer updates as you type: nothing is fixed in the code, so the result reflects exactly the numbers you supply.
The formula this calculator evaluates is printed under the tool and explained below, so you can check the working by hand or reuse it in a spreadsheet.
The formula
Formulamoles per element = mass ÷ atomic mass; divide every mole value by the smallest to get the ratio
The inputs explained
| Field | What to enter |
|---|---|
| Mass or mass % of each element (comma-separated) | A list of numbers, separated by commas or spaces. |
| Atomic mass of each element, same order (comma-separated) | A list of numbers, separated by commas or spaces. |