Chemical Equation Balancer
Type an unbalanced equation and get the smallest whole-number coefficients, an atom-by-atom check, the mass check, and the mole ratio.
Balancing by trial and error works until the equation has five or six substances. This balancer solves it exactly, then shows the proof your teacher wants to see: every element counted on both sides, the total charge for ionic and half-reaction equations, and the mass of reactants matching the mass of products. Use it to check your own answer after you have tried it on paper.
Atom check
Coefficient × subscript, added up on each side. Every row has to match.
| Element | Reactants | Products | Check |
|---|
Show your work
The atoms each substance contributes once its coefficient is in place.
Mass check
Law of conservation of mass: for the mole amounts in the balanced equation, both sides weigh the same.
| Substance | Side | Moles | g/mol | Grams |
|---|
How to type equations (and why it might not balance)
- Arrow: type
->,=, or tap the → button. Separate substances with+. - Capital letters matter.
Cois cobalt;COis carbon monoxide. Numbers after a symbol are subscripts, and a number after parentheses multiplies everything inside. - Don't type coefficients. If you do, they're ignored — the balancer works them out from scratch.
- Ions and half-reactions: put the charge after a caret —
Fe^3+,SO4^2-,H^+— and write electrons ase^-. Charge is balanced along with the atoms. - States like
(s),(l),(g)and(aq)are kept in the answer and don't affect the math. Hydrates use a dot:CuSO4·5H2O. - "Appears only on one side": an element is on one side of the arrow but not the other. A product or reactant is missing, or a formula has a typo.
- "More than one way to balance": the equation mixes two independent reactions, so the coefficients aren't fixed. Check the products your teacher gave you.
- Balanced doesn't mean it happens. This checks the bookkeeping of atoms and charge; it can't tell you whether a reaction actually occurs.
Everything runs in your browser. Your last equation is remembered on this device only.