Chemical Equation Balancer
Type the reactants and products with = or -> between them. Coefficients appear as you type.
Atom check
| Element | Left | Right | Status |
|---|---|---|---|
| C | 3 | 3 | ✓ balanced |
| H | 8 | 8 | ✓ balanced |
| O | 10 | 10 | ✓ balanced |
Try it yourself: balance by counting atoms
Coefficients multiply whole formulas. Use the + and − buttons and watch each element’s count on both sides. When every row matches, the equation is balanced.
Not balanced yet. Fix the element whose counts differ, starting with one that appears in only one formula per side.
Want the method explained?
AI answers can be wrong. The calculators on this page are deterministic; trust them for numbers.
Balancing equations step by step
- Write correct formulas for every reactant and product. Never change them afterwards.
- Count atoms of each element on each side.
- Balance elements that appear in only one compound on each side first. Metals, then nonmetals, then hydrogen, then oxygen usually works.
- Treat a polyatomic ion that appears unchanged on both sides (SO₄²⁻, NO₃⁻) as one unit.
- If you end up with a fraction (e.g. 7/2 O₂ for ethane), multiply every coefficient by the denominator.
- Check the counts once more, and for ionic equations check that the total charge matches too.
Once balanced, the coefficients are mole ratios. Use them in the stoichiometry calculator to find masses, the limiting reactant and theoretical yield.
Questions students ask
How do you balance a chemical equation?
Atoms are neither created nor destroyed, so every element must have the same count on both sides. Change only the coefficients (the big numbers in front), never the subscripts, because changing a subscript changes the substance. Start with the element that appears in the fewest formulas, leave hydrogen and oxygen until last, and finish by reducing to the smallest whole numbers.
How does this balancer work?
It writes one equation per element (atoms on the left = atoms on the right) and, for ionic equations, one for charge. Solving that system exactly with fractions and scaling to whole numbers gives the smallest integer coefficients. No guessing is involved, so it balances redox equations such as permanganate with hydrochloric acid in one step.
How do I type charges and electrons?
Put the charge after a caret: Fe^3+, MnO4^-, SO4^2-. For monatomic ions you can also write Fe3+ or Cl-. Type electrons as e-. State symbols such as (aq) or (s) are ignored.
Why can’t my equation be balanced?
The usual causes are a mistyped formula (NaCL instead of NaCl), an element that appears on only one side, or a product that isn’t actually formed. If two independent reactions are combined in one equation, there are infinitely many balanced forms; add or remove a species to pin it down.
Can I balance by the half-reaction method here?
The solver balances the full ionic equation directly, which gives the same result as combining half-reactions. You can also balance a single half-reaction by including e-, for example Cr2O7^2- + H^+ + e- = Cr^3+ + H2O.