Chemical Equation Balancer - Online Stoichiometry Solver

A chemical equation balancer is a tool that automatically finds the correct stoichiometric coefficients to obey the law of conservation of mass. It ensures the number of atoms of each element is the same on both sides of the equation.

Balancing reflects the law of conservation of mass – atoms are neither created nor destroyed. A balanced equation is essential for quantitative predictions in reactions, such as calculating reactant/product masses in stoichiometry.

Our tool parses each chemical formula, builds a linear system based on elemental counts, and uses Gaussian elimination with rational scaling to determine the smallest integer coefficients. The algorithm handles parentheses, nested groups, and common reaction formats.

This version focuses on neutral molecular equations. For ionic half‑reactions or redox balancing with charge, dedicated tools are needed. We plan to support charge balancing in a future update.

If the tool cannot find a valid set of coefficients, it means the equation does not conserve all elements. Check your input for typos, missing substances, or incorrect formulas. Ensure arrows and '+' signs are used correctly.

Simply type parentheses as you would in a normal chemical formula, e.g., Ca(OH)2. The parser handles nested groups like Fe2(SO4)3 correctly. Coefficients should not be placed before the formula – the balancer will determine them.

After balancing, choose a substance from the dropdown, enter its mass (in grams or moles), and click “Calculate”. The tool uses the stoichiometric ratios and molar masses to instantly compute the required masses of all other substances.

Molar masses are based on standard atomic weights (IUPAC) with four‑digit precision for common elements. For most stoichiometric calculations, this precision is more than sufficient.