Turn measured composition into the simplest formula. View mole normalization, factor scaling, and clean outputs. Download reports, inspect examples, and verify answers with charts.
Use up to six elements. Leave unused rows blank. The page stays single column overall, while calculator inputs use a 3-column large, 2-column medium, and 1-column mobile layout.
This worked example uses percent composition values for a compound containing carbon, hydrogen, and oxygen.
| Element | Percent by Mass | Atomic Mass | Moles | Normalized Ratio | Empirical Subscript |
|---|---|---|---|---|---|
| C | 40.00 | 12.011 | 3.3303 | 1.0000 | 1 |
| H | 6.71 | 1.008 | 6.6567 | 1.9988 | 2 |
| O | 53.29 | 15.999 | 3.3308 | 1.0002 | 1 |
| Example empirical formula | CH2O | ||||
Step 1: Convert each composition value into moles.
moles = entered value ÷ atomic mass
Step 2: Divide every mole value by the smallest mole value.
normalized ratio = moles ÷ smallest mole value
Step 3: If ratios are fractional, multiply all ratios by the same factor until they are close to whole numbers.
integer subscript = round(normalized ratio × factor)
Step 4: Write each element with its final whole-number subscript to obtain the empirical formula.
It shows the simplest whole-number ratio of atoms in a compound. It does not always match the molecular formula, which can be a whole-number multiple of the empirical result.
Yes. Percent composition values work because empirical formulas depend on ratios. Many students assume a 100 gram sample, which turns each percent directly into grams before converting to moles.
Atomic masses convert the entered composition values into moles. Without that conversion, the numbers represent mass only and cannot reveal the atom ratio needed for the simplest formula.
Some normalized ratios land near values like 1.5, 1.33, or 1.25. Multiplying all ratios by a shared factor can turn them into clean integers for the final empirical subscripts.
Small differences usually come from rounding in the entered data or atomic masses. Increase decimal precision, check your inputs, or widen the scaling factor limit to test additional ratio fits.
Yes. The form supports up to six elements in one calculation. Unused rows can stay blank, so the calculator remains flexible for both simple and more complex compounds.
No. Some compounds share the same empirical formula but have larger molecular formulas. For example, glucose has molecular formula C6H12O6, while its empirical formula is CH2O.
They include the calculated formula and the main result table with element data, atomic masses, moles, ratios, and final subscripts. The PDF is designed as a compact report for quick sharing.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.