The chemical equation balancer uses algebraic linear algebra to balance any chemical equation. Enter an unbalanced equation using standard notation (e.g., H2 + O2 -> H2O) and get the balanced form with coefficients.
Chemical Equation Balancer
How to Use the Chemical Equation Balancer
Enter your unbalanced equation using standard chemical notation. Separate compounds with + and separate reactants from products with -> or →.
Input Format
Element symbols must be capitalized properly: H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K, Ca, Fe, Cu, Zn, Ag, Au, Hg, Pb, etc. Subscripts are plain numbers after the element: H2O, CO2, C6H12O6. No spaces within a formula.
Examples
H2 + O2 -> H2O → balanced: 2H₂ + O₂ → 2H₂O
Fe + O2 -> Fe2O3 → balanced: 4Fe + 3O₂ → 2Fe₂O₃
C3H8 + O2 -> CO2 + H2O → balanced: C₃H₈ + 5O₂ → 3CO₂ + 4H₂O
Limitations
This balancer handles simple inorganic and organic reactions up to about 6 compounds. Complex multi-step reactions or those requiring half-reactions (redox) may need manual balancing. Parentheses in formulas (e.g., Ca(OH)2) are supported.
FAQ
How do you balance a chemical equation?
A balanced equation has equal numbers of each type of atom on both sides. Method: (1) Write the unbalanced equation. (2) Count atoms of each element. (3) Add coefficients (not subscripts) to balance, starting with the most complex molecule. (4) Check all atoms balance. Example: H₂ + O₂ → H₂O becomes 2H₂ + O₂ → 2H₂O.
What are the rules for entering formulas?
Use standard chemical notation: element symbols capitalized (Fe, Ca, H), subscripts as numbers after the symbol (H2O, CO2, C6H12O6). Parentheses work for polyatomic ions: Ca(OH)2. Use + to separate compounds, and -> or → to separate reactants from products. Example: Fe + O2 -> Fe2O3.
Is this calculator free?
Yes, completely free with no signup required. All calculations run in your browser.
Is my data private?
Yes. All calculations run locally. Nothing is transmitted.
Why must chemical equations be balanced?
The law of conservation of mass states that matter is neither created nor destroyed in chemical reactions. The total mass of reactants must equal the total mass of products. An unbalanced equation would imply atoms appearing or disappearing, which is physically impossible.