Donaldson R F Chemical Equation Balancer
Type an unbalanced equation and get the smallest whole-number coefficients, with a check of the atoms on each side.
How balancing works
A balanced equation has the same number of atoms of each element on both sides. This tool writes one equation per element (atoms on the left minus atoms on the right equal zero) and solves them exactly with fractions, then scales to the smallest whole numbers. It works for any equation that can be balanced by atom count, including redox reactions, and shows the atom totals so you can check the result.
Type formulas with capital letters for elements (Co is cobalt, CO is carbon monoxide), numbers for subscripts, brackets for groups, and a dot for hydrates (CuSO4.5H2O). State symbols such as (aq) are ignored; charges are not supported, so write ionic equations as full compounds. If an equation has more than one independent solution, it is probably several reactions written as one.