Chemical Equation Balancer

What this tool does

Type in a chemical equation like Fe + O2 -> Fe2O3 and it finds the smallest set of whole-number coefficients that balance every element on both sides — instantly, and without guesswork. It handles nested parentheses (like Ca(OH)2), multi-element formulas, and equations with any number of reactants and products, using exact fraction math rather than trial and error.

Who it's for

Chemistry students checking homework before it's due, teachers building worksheet answer keys, and anyone who just needs to double-check a reaction without hand-balancing it on paper.

How to use it

• Type an equation using + between compounds and -> or = between reactants and products, e.g. C3H8 + O2 -> CO2 + H2O.
• The balanced equation appears automatically as you type, with coefficients shown in front of each compound.
• Scroll down to the Atom Count Check table to see exactly how many atoms of each element show up on the left and right sides — they should always match once it's balanced.
• Try one of the example equations if you want to see it in action first, and use Copy to grab the result as plain text.

Real-world uses

Balancing combustion reactions like propane burning in oxygen, verifying a decomposition reaction such as potassium permanganate breaking down, or working through a stoichiometry problem where the balanced equation is the first step.

Frequently asked questions

Why do chemical equations need to be balanced at all?

The law of conservation of mass means atoms can't be created or destroyed in a chemical reaction — every atom present in the reactants has to show up somewhere in the products. Balancing finds the coefficients that make that true.

Does this handle ionic or redox equations with charges?

No — this tool balances standard molecular equations by atom count only. Equations involving ion charges (like Fe³♠) or half-reactions need charge-balancing on top of atom-balancing, which is outside what this tool does.

What if I get an error saying it can't be balanced?

That usually means a formula is mistyped, a compound is missing from one side, or the reaction as written isn't chemically valid. Double-check every formula's capitalization — chemical symbols are case-sensitive (Co is cobalt, CO is carbon monoxide).

Can I type an equation that already has coefficients in it?

Yes — any leading numbers you type (like the "2" in "2H2") are ignored, since the tool calculates the correct coefficients itself rather than trusting what's already there.

How does the tool actually solve for the coefficients?

It sets up one equation per element (atoms in must equal atoms out) and solves the resulting system using exact fraction arithmetic, then scales the result to the smallest possible whole numbers — the same underlying math as the "algebraic method" taught in chemistry courses, just automated.