Free · Private · Chemistry Lab
Chemical Equation Balancer
Balance molecular, ionic, and many redox equations with exact algebraic coefficients, atom/charge checks, and live mass–mole stoichiometry — all in your browser.
Main · balancer
Balance & stoichiometry
Enter a reaction to balance
Supports polyatomic ions, hydrates, phases, and many ionic / redox forms.
· Arrow: ->, =, or →
· Groups: Al2(SO4)3, [Cu(NH3)4]2+
· Hydrates: CuSO4·5H2O (middle dot, period, or *)
· Ions: Fe2+, SO4^2-, e-
· Phases: (s) (l) (g) (aq) at the end of a formula
A professional online equation balancer
Guess-and-check works for simple homework, but polyatomic salts, hydrates, and charged redox systems need a systematic approach. This chemical equation balancer assigns unknowns to each species and solves conservation equations with exact fractions, then reduces to the smallest whole-number coefficients. Continue into the Titration Simulator when your balanced reaction is an acid–base or redox titration.
BigInt fractions avoid floating-point drift so coefficients stay chemically correct even for messy redox systems.
Parse Fe2+, CuSO4·5H2O, Al2(SO4)3, and (aq)/(g)/(s)/(l) markers without losing charge or water of hydration.
Enter grams or moles once; theoretical amounts update for every reactant and product from the mole ratio.
See a conservation table that verifies left and right counts match before you copy the answer into a lab report.
How to balance equations with this tool
- 1
Type or paste the reaction
Example: Fe2(SO4)3 + KSCN -> K3[Fe(SCN)6] + K2SO4. Use = or -> between sides.
- 2
Review the balanced equation
Coefficients appear in the smallest whole numbers. Copy the equation or a shareable link.
- 3
Check atom conservation
Confirm each element (and charge, for ionic work) matches on both sides.
- 4
Run stoichiometry
Enter a known mass or mole amount to scale yields for homework or lab prep.
Frequently asked questions
How does this chemical equation balancer work?
It builds a system of linear equations from atom (and charge) conservation, then solves with exact rational arithmetic. Coefficients are scaled to the smallest positive integers — the same algebraic method taught in advanced chemistry courses.
Can it balance redox and ionic equations?
Yes for many cases. Include ions with charges like Fe2+, MnO4-, and H+, or electrons as e-. Charge is conserved along with atoms. If a half-reaction is missing H2O, H+, or OH-, add those species so a positive balance exists.
What formula syntax is supported?
Use element symbols (H2O, NaCl), parentheses or brackets for groups (Al2(SO4)3, [Cu(NH3)4]2+), hydrate dots (CuSO4·5H2O), and phase tags (s), (l), (g), (aq). Separators: =, ->, or →. Lowercase input like h2o is auto-corrected when possible.
Why did balancing fail?
Common causes: an element only on one side, missing species in a redox half-reaction, mismatched brackets, unknown element symbols, or an incomplete reaction. The error message names the specific issue when possible.
How do I use the stoichiometry table?
After a balance, enter mass (g) or moles for any species. The tool scales every other species by the mole ratio from the balanced equation so you can find theoretical amounts quickly.
Is my equation stored on a server?
No. Balancing runs entirely in your browser. Optionally sync the equation into the URL (?eq=…) so you can bookmark or share a link — still without uploading chemistry data to our servers.
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