Chemical Equation Balancer
Balance chemical equations and verify atom counts on both sides.
Enter reactants and products with an equals sign, arrow, or ->. The workspace balances coefficients, verifies atoms, estimates stoichiometry, and shows the algebra behind the answer.
Balance chemical equation
How to Use the Chemical Equation Balancer
1
Type the reaction. Enter reactants and products separated by an equals sign or arrow, for example CH4 + O2 = CO2 + H2O.
2
Balance. The tool assigns a variable to each compound, writes a conservation equation for every element, and solves for the smallest whole-number coefficients.
3
Verify and use the ratios. Check the per-element atom verification table, then enter amounts in the stoichiometry table to get the limiting reagent and predicted yields.
What is the Chemical Equation Balancer?
The chemical equation balancer finds the smallest whole-number coefficients that make atoms of every element equal on both sides of a reaction. Type an unbalanced equation like Fe + O2 = Fe2O3 and the tool returns the balanced equation, a per-element atom count, and the stoichiometric ratios you need for mole calculations.
Balancing is the foundation of stoichiometry: an unbalanced equation gives wrong mole ratios, wrong limiting reagents, and wrong yields. Use the balanced coefficients from this tool directly in the limiting reagent and percent yield calculators on this site.
Common Uses
- Balance combustion, synthesis, and decomposition reactions
- Verify atom counts on both sides of an equation
- Get mole ratios for stoichiometry homework
- Prepare balanced equations for lab reports
How to Solve It by Hand
Manual calculation is still important: identify the known variables, convert units before substitution, apply the equation, and check whether the result is chemically reasonable. The most common mistakes are inconsistent units, constants rounded too early, and skipping the interpretation step.
Practice Prompt
Try changing the default values and ask the lower-right chemistry chat why the result increased or decreased. That turns the calculator from a number machine into a study loop.
It assigns a variable to every compound, writes one conservation equation per element, and solves the resulting linear system with exact fraction arithmetic. The solution is then scaled to the smallest set of whole numbers. The full algebra is shown with the result.
Subscripts define what the substance is. Changing H2O to H2O2 turns water into hydrogen peroxide, which is a different reaction. Balancing only adjusts how many units of each substance react, which is what coefficients represent.
Use an equals sign, an arrow, or -> between reactants and products, and a plus sign between species: CH4 + O2 = CO2 + H2O. Parentheses and brackets are supported, and spacing is ignored.
That usually means an element appears on one side only, a formula has a typo, or the reaction as written is not chemically possible. Check that every element on the left also appears on the right, and that each formula is spelled with correct capitalisation such as Co for cobalt and CO for carbon monoxide.
Yes. Once the equation is balanced, enter the moles or grams you have of each species in the stoichiometry table and the tool reports the reaction extent, the limiting reagent, and the predicted amount of every other species.