liminfoChemical Equation Balancer
Free web tool: Chemical Equation Balancer
Chemical Equation Balancer
Balance simple chemical equations. Use + between compounds and = to separate sides.
Balanced Equation
2H2 + O2 → 2H2O
About Chemical Equation Balancer
The Chemical Equation Balancer automatically determines the stoichiometric coefficients needed to satisfy the law of conservation of mass for a chemical reaction. Type your unbalanced equation using element symbols separated by + on each side of the = sign — for example, H2 + O2 = H2O — and the tool instantly returns the balanced form with the smallest whole-number coefficients.
Balancing chemical equations is a fundamental skill in chemistry education and a necessary step in any quantitative analysis of reactions. The tool supports compound formulas with parenthetical groups such as Ca(OH)2, and it handles reactions involving up to six compounds across both sides. The algorithm works by brute-force search over integer coefficient combinations from 1 to 10, ensuring the atom count for every element is equal on both sides of the arrow.
All processing is performed client-side in your browser. Six preset reactions — including combustion, synthesis, and displacement reactions — are available as one-click examples to help you get started quickly. The tool is free, requires no account, and works on any device.
Key Features
- Instant balancing of chemical equations with up to 6 compounds across both sides
- Supports parenthetical groups in formulas such as Ca(OH)2, Al2(SO4)3, and Fe(NO3)3
- Six built-in preset reactions: water formation, iron oxidation, methane combustion, ammonia synthesis, propane combustion, and aluminum-HCl reaction
- Returns the smallest whole-number stoichiometric coefficients that satisfy mass conservation
- Clear error message when the equation cannot be balanced (e.g., too many compounds or invalid formula)
- 100% client-side — no data is ever sent to a server
- Dark mode support for comfortable use in any lighting environment
- No sign-up, no download, and completely free to use
Frequently Asked Questions
How do I enter a chemical equation?
Type the reactants on the left side separated by +, then =, then the products on the right side separated by +. For example: Fe + O2 = Fe2O3. Use uppercase letters for element symbols (Fe, Ca, Na) and lowercase for the rest of the symbol (e.g., Fe, not fe). Numbers after a symbol indicate subscripts.
What does balancing a chemical equation mean?
Balancing means finding whole-number coefficients for each compound so that the total number of atoms of each element is the same on both sides of the equation. This satisfies the law of conservation of mass — matter cannot be created or destroyed in a chemical reaction.
Can I use parentheses in formulas?
Yes. The parser handles parenthetical groups with multipliers, such as Ca(OH)2, Al2(SO4)3, and Fe(NO3)3. Place the multiplier immediately after the closing parenthesis.
Why does the balancer fail for some equations?
The tool searches for integer coefficients between 1 and 10 for each compound. If the balanced equation requires coefficients larger than 10, or if the equation contains more than 6 compounds, the search will not find a solution. Try simplifying the equation or splitting it into sub-reactions.
What are the preset reaction examples?
The six presets are: H2 + O2 = H2O (water formation), Fe + O2 = Fe2O3 (iron oxidation), CH4 + O2 = CO2 + H2O (methane combustion), N2 + H2 = NH3 (ammonia synthesis), C3H8 + O2 = CO2 + H2O (propane combustion), and Al + HCl = AlCl3 + H2 (displacement reaction).
Does the tool handle ionic or half-reactions?
No. The current balancer works with molecular formulas and counts atoms only. It does not balance ionic charges, handle half-reactions for redox processes, or account for spectator ions. For those cases, you will need to balance the equation manually or use a more advanced chemistry tool.
Can I balance equations with more than two reactants?
Yes, up to a total of 6 compounds (reactants + products combined) are supported. For example, A + B + C = D + E + F is within scope. Equations with 7 or more compounds may not be solved by this tool.
Is this suitable for high school and university chemistry courses?
Yes. The balancer covers the types of reactions commonly encountered in high school and introductory university chemistry: combination, decomposition, single displacement, double displacement, and combustion reactions. The preset examples include classic textbook reactions.