Enter the reaction
Type reactants, products, plus signs, and one reaction arrow.
Reaction balancing tool
Chemical Equation Balancer
Enter an unbalanced chemical reaction to find the smallest whole-number coefficients, verify atom conservation, and review a clear element-by-element balance table.
Automatic coefficients
Atom conservation check
Parentheses support
Reaction input
Enter an unbalanced equation
Separate substances with plus signs and use an arrow between reactants and products. Existing coefficients may be included.
Supported syntax
Supports standard element symbols, parentheses, square brackets, hydrates, and state labels such as (s), (l), (g), and (aq). Ionic charge notation is not supported in this version.
Balanced result
Conservation breakdown
Your balanced equation will
appear here
Enter a valid reaction to calculate the smallest whole-number coefficient ratio and verify every element.
Simple balancing process
How the chemical equation balancer works
The tool converts each formula into element counts, builds a conservation matrix, and solves for the smallest positive whole-number ratio.
Count every atom
The calculator expands groups and counts each element in every substance.
Solve the coefficient matrix
Exact fraction arithmetic is used to find a valid null-space solution.
Verify conservation
The final coefficients are reduced and every element is checked on both sides.
What is a chemical equation balancer?
A chemical equation balancer calculates the coefficients required to make the number of atoms of each element equal on the reactant and product sides of a chemical reaction.
Balancing changes only the coefficients placed before formulas. Subscripts inside a chemical formula must never be changed because they define the identity of the substance.
Law of conservation of mass
Chemical reactions rearrange atoms. They do not create or destroy them. A balanced equation therefore contains the same total number of atoms of every element before and after the reaction.
Coefficient rules
- Use whole-number coefficients whenever possible.
- Reduce coefficients to the smallest common ratio.
- Do not alter subscripts inside formulas.
- Check every element after balancing.
Supported examples
The calculator can handle combustion, synthesis, decomposition, single-replacement, double-replacement, and many neutral redox equations.
Helpful answers
Frequently asked questions
Learn more about coefficients, atom conservation, formula syntax, and automatic equation balancing.
What is a chemical equation balancer?
A chemical equation balancer finds the smallest whole-number coefficients that make the number of atoms of every element equal on both sides of a reaction.
Why must chemical equations be balanced?
Chemical equations must follow the law of conservation of mass. Atoms are rearranged during a reaction, but they are not created or destroyed.
How should I enter an equation?
Enter reactants and products separated by plus signs and an arrow, such as H2 + O2 -> H2O. Standard parentheses and square brackets are supported.
Can I include existing coefficients?
Yes. Existing leading coefficients are accepted, but the calculator recalculates and returns the smallest valid whole-number ratio.
Does the calculator support state symbols?
Yes. Common state symbols such as (s), (l), (g), and (aq) can be included at the end of a formula and are preserved in the displayed result.
Can it balance ionic equations with charges?
This version is designed for ordinary molecular equations. For ionic equations, enter neutral formulas without charge symbols because plus and minus signs can be confused with equation separators.
What happens if an equation cannot be balanced?
The calculator shows a clear error when formulas are invalid, an element appears on only one side, or no positive whole-number coefficient set can be found.