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Chemical Yield calculator.

Calculate the chemical yield (% yield) of any reaction from the actual isolated mass and the theoretical yield derived from the limiting reagent. Results update live as you type — and every session stays in your browser, never on a server.

Principle 2 guide
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What is Chemical Yield — and why does it matter?

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Chemical yield (% Yield) measures how much of the theoretically possible product was actually isolated in practice, expressed as a percentage. It compares what you got in the flask to what stoichiometry says you should have been able to make — and the gap between the two represents losses from incomplete reaction, side reactions, purification steps, and handling. A high % yield means the reaction has been run efficiently, generating less waste and requiring fewer raw materials per gram of purified product.

GoalMaximise the fraction of theoretical product actually isolated — approaching 100% yield means minimal waste, minimal unreacted starting material, and maximum use of purchased reagents.
WhyEvery percentage point of lost yield is both an economic and an environmental cost: unused reagents become waste, purification consumes solvents and energy, and scale-up amplifies every inefficiency.
HowOptimise reaction conditions (temperature, concentration, time), select a selective catalyst to suppress side reactions, improve work-up and isolation procedures, and consider in-line analysis to detect and correct losses in real time.

The formula

$$\% \text{Yield} = \frac{m_{\text{actual}}}{m_{\text{theoretical}}} \times 100$$
SymbolTermUnits
$\% \text{Yield}$Percentage yield%; ideal = 100%
$m_{\text{actual}}$Mass of pure, dry product actually isolatedg
$m_{\text{theoretical}}$Theoretical yield: moles of limiting reagent × stoichiometric ratio × MW of productg

Note: % Yield uses the actual isolated mass — a product still in solution or not yet dried is not fully isolated. Theoretical yield assumes 100% conversion with no side reactions. Values above 100% indicate impurity in the product, incomplete drying, or a calculation error.

Typical chemical yield by reaction and context

ContextTypical % YieldReason
Industrial optimised process> 90%Highly optimised conditions, continuous monitoring, minimal handling losses
Excellent lab synthesis80–95%Well-optimised procedure, clean reaction, efficient isolation
Good undergraduate result60–80%Good technique; some losses from transfer, recrystallisation, or drying
Moderate / acceptable40–60%Incomplete reaction or significant purification losses; review conditions
Poor — needs investigation< 40%Major losses from side reactions, poor selectivity, or handling; systematic review required

Strengths and limitations

Strengths

  • Simple, universal metric understood across all levels of chemistry
  • Directly reflects experimental skill, procedure quality, and reaction optimisation
  • Scales directly to economic and environmental cost per gram of product
  • Captures losses from all sources: side reactions, isolation, handling
  • Can be tracked across a series of experiments to monitor improvement

Limitations

  • Says nothing about atom economy — a high-yield reaction can still waste most of the reactant mass as by-products by design
  • Does not capture waste from solvents, auxiliaries, or energy use
  • Theoretical yield ignores all by-products, assuming 100% selectivity
  • Values > 100% indicate errors (impurity, incomplete drying) — not a real result
  • Must be paired with Atom Economy and E-factor for a full green chemistry assessment

Chemical yield in context: complementary green metrics

MetricWhat it measuresStage
% YieldFraction of theoretical product actually isolated — experimental efficiencyExperimental
Atom Economy (AE)Theoretical fraction of reactant mass incorporated into desired product by designDesign
Reaction Mass Efficiency (RME)AE × yield × stoichiometric factor — combines design and experimental efficiencyBoth
E-factorMass of all waste per mass of product (includes solvents, excess reagents)Experimental
Space Time Yield (STY)Product mass per reactor volume per unit time — reactor productivityExperimental
PMI (Process Mass Intensity)Total mass of all inputs per mass of product; E-factor + 1Experimental
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Experiment details

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Reactants

Enter all reactants. MW and mass are required to identify the limiting reagent and calculate the theoretical yield. The limiting reagent is marked with ★.

Compound name Formula MW (g/mol) Mass used (g) Coeff. Moles
Σ Reactant mass g total mass of all reactants
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Product & actual yield

Enter the desired product and its MW so the theoretical yield can be calculated. Then enter the actual mass you isolated.

Product name Formula MW (g/mol) Coeff. MW × n
Theoretical yield from limiting reagent  ·  Limiting reagent:
g Enter the mass of pure, dry product recovered
Include stoichiometric coefficients in calculation
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Results

% Yield
percent
Theoretical Yield
grams
Actual Mass
grams isolated
Mass Not Isolated
grams
% Yield (higher is better)
0%25%50%75%100%

Reactant mass contributions

Actual vs. theoretical yield

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Detailed breakdown & interpretation

CompoundRoleFormulaMW (g/mol) Mass (g)MolesCoeff.% of reactantsVisual
Enter reactants, product, and actual mass above to see breakdown.

Interpretation

Enter reactants, product, and actual mass above to generate an interpretation.
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Save & load sessions

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Export

Export your % Yield calculation as a PDF report or CSV data file. PDF opens in a new tab and uses your browser's print function. CSV downloads directly.

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Where can I read more?

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References are sorted alphabetically by first author.

  1. ACS Green Chemistry Institute. Green Chemistry Resources & Solvent Selection Guide. acs.org/greenchemistry. — Pharmaceutical Roundtable solvent-selection scoring and PMI benchmarking data.
  2. P. T. Anastas and J. C. Warner, Green Chemistry: Theory and Practice, Oxford University Press, 1998. ISBN 978-0-19-850698-0. — Original statement of the 12 Principles; Principle 2 frames atom economy alongside yield.
  3. D. J. C. Constable et al., Green Chem., 2002, 4, 521–527. DOI. — Metrics to 'green' chemistry — which are the best? Compares yield, AE, E-factor, RME.
  4. R. A. Sheldon, Chem. Ind., 1992, 903–906. — Introduces E-factor; contextualises yield within the wider waste landscape.
  5. B. M. Trost, Science, 1991, 254, 1471–1477. DOI. — Introduces atom economy; discusses the relationship between yield and selectivity.
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Contributors

Roles follow the CRediT taxonomy (Contributor Roles Taxonomy), adapted for educational software. Hover a contributor's name for a summary, or a column header for the definition of that role.

Contributor

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This portal was built with the assistance of a large language model (Claude, Anthropic), which was used to generate and refine code, articulate and structure contributed ideas within the defined page format, and support iterative design decisions. All scientific content, conceptual frameworks, pedagogical choices, and final outputs were directed, reviewed, and verified by the contributors listed above.

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How do I cite this page?

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If you use this tool in teaching or published work, please cite the DodecaGreen portal as the source.

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