Theoretical Yield Calculator

Inputs

Provide coefficients from a balanced equation. At least one reactant must be supplied. All masses in grams and molar masses in g/mol.

Reactant A

Coefficient (a)

Molar mass A (g/mol)

Mass A (g)

Reactant B

Coefficient (b)

Molar mass B (g/mol)

Mass B (g)

Reactant C (optional)

Coefficient (c)

Molar mass C (g/mol)

Mass C (g)

Product

Coefficient (p)

Molar mass Product (g/mol)

Actual yield (g) (optional)

Results

Run a calculation to see outputs here.

Formula Used

The balanced reaction is written as a·A + b·B (+ c·C) → p·P.

Moles of each reactant: n = m / M where m is mass (g) and M is molar mass (g/mol).
Reaction extent based on each reactant: ξ_i = n_i / coefficient_i.
Limiting reagent gives ξ = min(ξ_A, ξ_B, ξ_C).
Moles of product: n_P = ξ · p.
Theoretical yield (g): m_P,theory = n_P · M_P.
Percent yield (optional): % yield = 100 × (m_P,actual / m_P,theory).

Example Data Table

Click Load to populate the inputs with an example.

Reaction	a	b	p	M_A	M_B	M_P	m_A	m_B
2 H₂ + O₂ → 2 H₂O	2	1	2	2.016	32.00	18.01528	4	32
N₂ + 3 H₂ → 2 NH₃	1	3	2	28.0134	2.016	17.0305	14	6
2 Al + 3 Cl₂ → 2 AlCl₃	2	3	2	26.9815	70.906	133.3405	10	50
C₆H₁₂O₆ + 6 O₂ → 6 CO₂	1	6	6	180.156	32.00	44.01	18	32

How to Use

Balance the reaction and enter the stoichiometric coefficients for each species.
Provide masses and molar masses for available reactants. Leave reactant C as zero if unused.
Enter the product coefficient and molar mass.
Click Calculate to determine the limiting reagent, product moles, and theoretical yield in grams.
Optionally enter an actual yield to compute percent yield.
Export your result or the example table to CSV or PDF.

FAQs

1) What units should I use?
Enter masses in grams and molar masses in grams per mole. The calculator reports theoretical yield in grams.

2) How is the limiting reagent determined?
For each reactant the ratio of moles to its coefficient is computed and the smallest ratio indicates the limiting reagent.

3) Can I include more than two reactants?
Yes. Use Reactant C fields. Leave them as zero when your reaction uses only two reactants.

4) Do I need a balanced equation?
Yes. Coefficients must come from a balanced reaction otherwise results will be incorrect.

5) How accurate are results?
Calculations are purely stoichiometric. Real experiments may differ due to side reactions losses purity and measurement error.

6) What if I only know moles not masses?
Convert your moles to mass using m = n · M then enter the mass and molar mass.

7) Can I compute percent yield?
Enter an actual product mass in the optional field. The calculator will compute percent yield automatically.