⚗️Chemical Equation Balancer

About this tool

Type the unbalanced equation with + between substances and = or -> between reactants and products, for example Fe + O2 = Fe2O3, or tap one of the examples. The balanced equation appears with subscripts, and a table confirms that every element has the same count on both sides. Existing coefficients are ignored.

How chemical equations are balanced

A chemical reaction rearranges atoms but never creates or destroys them, so a balanced equation has the same number of each kind of atom on both sides. Balancing means finding the smallest whole-number coefficients that make this true. By hand, you adjust coefficients one element at a time, which works for simple reactions but becomes slow for complex ones. This tool writes one equation for each element, counting atoms on each side, and solves the whole system exactly with fractions, then scales the answer to the smallest whole numbers. Iron rusting, Fe + O₂ → Fe₂O₃, balances as 4 Fe + 3 O₂ → 2 Fe₂O₃; burning propane gives C₃H₈ + 5 O₂ → 3 CO₂ + 4 H₂O; and the redox reaction between potassium permanganate and hydrochloric acid needs 2, 16, 2, 2, 8 and 5. Brackets such as Ca(OH)₂ and Ca₃(PO₄)₂, hydrates such as CuSO₄·5H₂O, and charges such as Fe^3+ are understood, so ionic equations balance charge as well as atoms. If an equation could balance in more than one independent way, it's usually two reactions written together, and the tool says so. Honest limits: balancing only checks conservation of atoms and charge. It can't tell you whether a reaction actually happens, predict the products or show physical states. The molar mass calculator, the molarity calculator and the empirical formula calculator are related.

Frequently asked questions