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Stoichiometry Calculators

Chemical Equation Balancer

Balance any chemical equation automatically and see the coefficients and atom counts on each side.

Enter values

Results update as you type.

Result

Balanced equation

C3H8 + 5O2 → 3CO2 + 4H2O

Reactant coefficients
1, 5
Product coefficients
3, 4
Total moles of reactant
6
Step-by-stepShow
  1. 1 × C3H8 = 44.097 g per mole set
  2. 5 × O2 = 159.99 g per mole set
  3. 3 × CO2 = 132.027 g per mole set
  4. 4 × H2O = 72.06 g per mole set

Atom balance check

ElementLeft sideRight sideBalanced
C33Yes
H88Yes
O1010Yes

About the Chemical Equation Balancer

A balanced equation has the same number of atoms of each element on both sides. This balancer sets up the element matrix for your reaction and solves it exactly, so it handles everything from simple combustion to redox reactions with six or more species.

Also known as: balance chemical equation, equation balancer, balancing equations, reaction balancer, balance reaction.

How to use this calculator

  1. Write the reaction with + between compounds and -> or = between the sides.
  2. Use capital letters for element symbols and brackets for groups.
  3. The balancer returns the smallest whole-number coefficients.

Formula

Atoms of each element must match on both sides

Worked example

Using the values pre-filled in the calculator above:

  • Unbalanced equation: C3H8 + O2 -> CO2 + H2O

the calculator returns:

  • Balanced equation: C3H8 + 5O2 → 3CO2 + 4H2O
  • Reactant coefficients: 1, 5
  • Product coefficients: 3, 4
  • Total moles of reactant: 6

Working

  1. 1 × C3H8 = 44.097 g per mole set
  2. 5 × O2 = 159.99 g per mole set
  3. 3 × CO2 = 132.027 g per mole set
  4. 4 × H2O = 72.06 g per mole set

Frequently asked questions

What if my equation cannot be balanced?

Check that every element on the left also appears on the right. Reactions that need an extra species (like water or H⁺) cannot balance until you add it.

Does it handle ionic equations?

It balances atoms, not charges. For redox half-equations, balance atoms here and then add electrons by hand.