Balance Formula Calculator
Balance formula calculator works out Balanced equation and Coefficients, left to right from Chemical equation. The default figures on this page give balanced equation of C3H8 + 5O2 → 3CO2 + 4H2O; change any entry and the result, the working and the sources update together.
Your figures
Updates as you typeHow this is worked out
6 steps
- Species, left to right: C3H8, O2, CO2, H2O
- Each element gives one conservation equation; solving them exactly over the rationals gives the smallest whole-number coefficients.
- C: 3 atom(s) left, 3 right
- H: 8 atom(s) left, 8 right
- O: 10 atom(s) left, 10 right
- Balanced: C3H8 + 5O2 → 3CO2 + 4H2O
Coefficients, left to righttable
Reactantstable
| formula | coefficient |
|---|---|
| C3H8 | 1 |
| O2 | 5 |
Productstable
| formula | coefficient |
|---|---|
| CO2 | 3 |
| H2O | 4 |
Atoms of each element on each sidetable
| element | reactantAtoms | productAtoms |
|---|---|---|
| C | 3 | 3 |
| H | 8 | 8 |
| O | 10 | 10 |
Its 5 worked examples are re-run on every release, last on 15 September 2026. What changed
Sources and references
3 sources
What the balance formula calculator calculates
Balances a chemical reaction from its formulas, solving element and charge conservation exactly and reporting the smallest whole-number coefficients.
How to use this balance formula calculator
Enter Chemical equation. Balanced equation updates as you type, and “Use a worked example” loads checked figures you can adjust. Change one figure at a time to see what drives the result.
How the result is worked out
Open “How this is worked out” beside the result for the step-by-step calculation behind Balanced equation, Coefficients, left to right and Reactants.
The method follows OpenStax Chemistry 2e, section 4.1 Writing and Balancing Chemical Equations, IUPAC Compendium of Chemical Terminology (Gold Book), "chemical equation" and Blakley, G. R., "Chemical equation balancing: a general method which is quick, simple, and has unexpected applications", Journal of Chemical Education 59(9) 728.
Synthesis of water example
With Chemical equation: H2 + O2 -> H2O, the calculator returns Coefficients, left to right: see result table, Balanced equation: 2H2 + O2 → 2H2O, Balanced: true. This example is checked against an independent source in the test suite.
What you can compare
Change one input at a time to see how it affects Balanced equation, Coefficients, left to right and Reactants. The inputs you can vary are Chemical equation.
Results are general information, not financial, tax, legal, medical or engineering advice. Check any decision that matters with a qualified professional.
See something wrong? Report a problem with this calculator
Frequently asked questions
What is the equation for balance?
On the figures this page opens with, the balanced equation is C3H8 + 5O2 → 3CO2 + 4H2O. No single number fits everyone: it follows Chemical equation, so enter your own above and the answer updates as you type.
Is there an easy way to balance equations?
Balances a chemical reaction from its formulas, solving element and charge conservation exactly and reporting the smallest whole-number coefficients. Put your own figures in above and the working updates beside the result. For scale, the default figures on this page give C3H8 + 5O2 → 3CO2 + 4H2O.
Where can I find a balance chemical equation calculator?
It needs Chemical equation. Nothing else is required, and the figures stay in your browser.
What is the formula of a balanced equation?
The result gives Balanced equation, Coefficients, left to right, Reactants, Products, Atoms of each element on each side and Balanced, each labelled with its unit so the figure can be read on its own.
What information do I need for the balance formula calculator?
You need Chemical equation. The page opens with default figures that give balanced equation of C3H8 + 5O2 → 3CO2 + 4H2O, so you can see the scale before entering your own.
What does this balance formula calculator show?
It shows Balanced equation, Coefficients, left to right, Reactants, Products, Atoms of each element on each side, Balanced and Independent balanced reactions, with the working and any warnings for your entries.