How to use the empirical formula calculator
Prepare the values for this calculation
Reduce entered element molar amounts to the smallest near-integer empirical-formula ratio. Use the formula below to check that it answers your question. Read the input units before transferring figures from a statement, measurement or dataset.
Enter and check each input
- Element:moles pairs (comma/new-line separated): use the same separators and value order as the example in the input table. Replace the example data with your own complete dataset.
The input table gives a complete example. Keep units and time periods consistent across related fields.
Calculate and resolve any input error
Choose Calculate after entering the values. Changes also update the answer after a short pause. If an error appears, follow its message, correct the field and calculate again. Reset restores the example values.
Interpret the answer
Check Empirical formula first. With the unchanged example inputs, it is CH2O. Compare the additional metrics with the primary result; each has its own label and unit.
Compare and keep a useful result
The result diagram shows the inputs, method and output. A numeric chart is shown only when the calculation supports a meaningful numeric relationship.
Use Copy result or Download CSV to keep the answer. Share tool shares the page address without placing your input values in the URL. Recheck inputs and assumptions before using the result for a decision.
Empirical Formula Calculator formula
Divide all molar amounts by the smallest, then find the smallest multiplier (1–12) yielding near integers.
Inputs and units
| Input | Format / range | Example |
|---|---|---|
| Element:moles pairs (comma/new-line separated) | Text / numeric list | C:0.4, H:0.8, O:0.4 |
Worked example
Using the example inputs above, the empirical formula is CH2O.
- Empirical formula
- CH2O
- Multiplier used
- 1
- Normalized ratios
- C:1, H:2, O:1
Results and assumptions
Uses entered molar amounts directly; convert measured masses to moles before using this tool.
Fix an input or unexpected result
If your answer differs from the example, choose Reset and compare every field, including selected units and options. Check percentage versus decimal entry and whether values describe the same period. Round only the final displayed answer when reproducing the formula.
If a discrepancy remains, report the calculator issue with the page address, non-sensitive example inputs, actual result, expected result and a reference for your calculation.