This tool checks whether the coefficients you type balance a chemical equation. It counts the atoms of each element on both sides and shows where they differ.
Free tool · Chemistry
Chemical equation balance checker
You keep changing numbers in an equation and the atoms still do not match.
Everything you enter stays on this device.
Who is this tool for?
It helps a student who balances by trial and error and cannot see why a change does not work. It also helps a student checking homework answers.
How do I use it?
- Choose an equation from the list.
- Type a whole-number coefficient for each substance. Every box starts at 1.
- Press “Check my balance”.
- Read the atom-count table. Each row is one element, with its count on the left and right.
- Change the coefficients and check again until every row matches.
How does it work?
For each element, the tool multiplies the coefficient by the subscript and adds over every substance on that side. The equation balances when all elements match on both sides.
The ionic example also compares the total charge. The tool finds the smallest whole-number set by searching coefficients from 1 to 12.
What does a worked example look like?
Take CH₄ + O₂ → CO₂ + H₂O with all coefficients 1. Carbon matches at 1 and 1. Hydrogen is 4 on the left and 2 on the right, and oxygen is 2 on the left and 3 on the right.
Put 2 in front of H₂O. Hydrogen becomes 4 and 4, and oxygen on the right becomes 2 + 2 = 4. Put 2 in front of O₂ to make 4 on the left. The balanced set is 1, 2, 1, 2.
What can the tool not tell you?
It does not predict reactions, show state symbols or accept edited formulas. Its list of equations is fixed, so it cannot check one you invent.
Balancing is one skill. Knowing what happens in a reaction is another, and the lessons below treat them separately.
Where does this connect to the lessons?
The main idea is in learning chemical equations without treating subscripts as coefficients. Ionic equations appear in the redox and equilibrium practice.
After balancing, try a calculation with the mole and stoichiometry steps. For lessons with a teacher, see Chemistry tuition and the one-hour trial class (from RM50).
Common questions
Why can I not change a subscript to balance an equation?
A subscript is part of the substance. Changing H₂O to H₂O₂ gives hydrogen peroxide, a different substance. Only the coefficient in front of a formula can change, because it counts how many of that substance take part.
What does the smallest whole-number set mean?
A balanced equation can be scaled up, such as 4, 2, 4 instead of 2, 1, 2. The smallest set is the one with no common factor in the coefficients. Exams normally expect the equation written this way.
Can the tool tell me what products form?
No. It checks atoms and charge for a fixed list of reviewed equations. It cannot predict whether a reaction happens or what forms, so you still need to learn the reactions themselves.
If balancing still feels like guessing, a teacher can practise a reliable method with you on your own equations in a one-to-one lesson.
- Online one-to-one lessons for your child with an experienced teacher.
- Your first class is a one-hour trial, from RM50. The fee is agreed before you book.
- Happy with the teacher? Continue with lessons of about 1.5 hours. If not, ask for another teacher.