Chemical Equation Balancer
Practise with 1,700+ real equations, or type your own and balance it with charges.
Separate species with + (spaces around the plus). Use plain numbers for subscripts: Ca(OH)2. For ions write the charge with a caret: Cu^2+, Fe^3+, e^-, SO4^2-. Charge is balanced too.
About the Chemical Equation Balancer
Free chemical equation balancing practice with more than 1,700 equations across combustion, synthesis, decomposition, replacement, precipitation, acid-base, organic and redox reactions. Type your own equation (ions and charges too) and balance it yourself or get the answer with a check of every atom. Built for reactions & kinetics, the chemical equation balancer runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Practise with 1,700+ real equations, or type your own and balance it with charges. Use it to explore reactions & kinetics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Chemical Equation Balancer
- Use the controls to change Difficulty, Type of reaction. The simulation reacts instantly.
- Pick an option such as All, Easy, Medium, Hard to switch modes or load an example.
- Press "New equation", "Hint", "Show answer", "Reset" to start, reset or change what is happening.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Pick Hard and Combustion, then balance a large hydrocarbon.
- Switch to Your own equation and type MnO4^- + Fe^2+ + H^+ -> Mn^2+ + Fe^3+ + H2O. Charge must balance too.
- Use Hint when stuck, and try to finish a streak of five without help.
- Filter by Acid-base to practise neutralisation reactions.
Key ideas you can learn
- Atoms are neither created nor destroyed, so both sides need the same count of each element.
- Change coefficients, never the subscripts inside a formula.
- Balance elements that appear in one compound on each side first, and leave O and H for last.
Where this is used in the real world
Balancing equations is the first step of every chemistry calculation, from lab yields to industrial reactors, fuels and medicine manufacturing.
Who is this simulation for?
Students learning reaction rates, equilibrium and equations, and teachers who want a visual way to explain what happens to particles.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
Why can't I change the subscripts to balance an equation?
Subscripts define what the substance is. Changing H₂O to H₂O₂ makes hydrogen peroxide, a different compound. Only coefficients can change.
What is the law of conservation of mass?
In a chemical reaction the total mass of the reactants equals the total mass of the products, because atoms are only rearranged.
Is the Chemical Equation Balancer free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Chemical Equation Balancer work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.