Chemical Equation Balancer
Balancing chemical equations is a rite of passage in chemistry, and a genuine sticking point for many students, because it means juggling coefficients until every element has exactly the same number of atoms on both sides, as the conservation of mass demands. This balancer does that work for you in an instant and, importantly, does it properly: rather than guessing and checking, it reads each formula, counts the atoms of every element, sets up the system of equations that mass balance requires, and solves it mathematically for the smallest set of whole-number coefficients. Type the reactants and products separated by plus signs, with an equals sign or an arrow between the two sides, for example propane burning as C3H8 + O2 = CO2 + H2O, and the balanced equation appears with the correct numbers in front of each substance. It understands ordinary chemical notation, including element symbols, subscripts, and brackets such as the hydroxide group in Ca(OH)2, so you can balance everything from simple combustion and synthesis reactions to more involved equations with polyatomic groups. Because it works from the underlying atom-counting equations, it handles cases that are awkward to balance by inspection, and when an equation genuinely cannot be balanced, because the formulas as written cannot conserve every element, it tells you so, which is a useful prompt to check your chemistry. This makes it a reliable companion for NCEA and senior chemistry, for first-year university courses, and for anyone needing the coefficients for a stoichiometry calculation, a lab preparation or homework. Used well, it is also a learning aid: balance an equation, then study the numbers to see how the atoms reconcile. The method and a worked example are explained clearly below.
Enter reactants and products separated by + with = or -> between the sides. Supports brackets like Ca(OH)2. Estimate aid for learning; always check important results.
How it works
The balancer parses each formula into a count of atoms per element, then builds one equation per element saying the atoms on the left must equal the atoms on the right. Treating the coefficients as unknowns, this is a system of linear equations, solved here with exact fraction arithmetic to find the proportions, which are then scaled to the smallest whole numbers. This is the same reasoning as balancing by inspection, done systematically.
Worked example
For C3H8 + O2 = CO2 + H2O, carbon balance gives 3 CO2 per propane, hydrogen balance gives 4 H2O, and oxygen balance then needs 5 O2. The balanced equation is C3H8 + 5 O2 = 3 CO2 + 4 H2O, with 3 carbons, 8 hydrogens and 10 oxygens on each side.
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