Atom Economy Calculator
Our stoichiometry calculator computes atom economy accurately. Enter measurements for results with formulas and error analysis.
Formula
Atom Economy = (MW of desired product / total MW of reactants) * 100%
Atom economy measures the fraction of reactant atoms that end up in the desired product. Higher atom economy means less waste. It is calculated from molar masses in the balanced equation, not from actual experimental quantities.
Frequently Asked Questions
What is atom economy?
Atom economy (or atom efficiency) measures how much of the reactant atoms end up in the desired product rather than in waste byproducts. It is calculated as (molecular weight of desired product / total molecular weight of all reactants) times 100%. A reaction with 100% atom economy converts all reactant atoms into product with no waste. Addition reactions typically have high atom economy, while substitution and elimination reactions produce byproducts and have lower atom economy. This concept was introduced by Barry Trost in 1991 as a key metric for green chemistry.
How is atom economy different from percent yield?
Atom economy is a theoretical measure based on the balanced equation that indicates the maximum possible efficiency of a reaction, regardless of how well it is actually carried out. Percent yield measures how much of the theoretical product was actually obtained in practice. A reaction can have 100% yield but poor atom economy if it produces lots of byproducts by design. The overall efficiency combines both: overall efficiency = (atom economy * percent yield) / 100. Green chemistry aims to maximize both metrics simultaneously.
Which types of reactions have the best atom economy?
Addition reactions and rearrangement reactions have the best atom economy, often achieving 100% because all atoms from the reactants are incorporated into a single product. Examples include the Diels-Alder reaction, hydrogenation, and polymerization. Substitution reactions have moderate atom economy because they exchange one group for another, producing a leaving group as waste. Elimination reactions tend to have lower atom economy because they remove atoms from the substrate. Multi-step syntheses compound the problem, as each step with less than 100% atom economy reduces the overall efficiency.
How do I get the most accurate result?
Enter values as precisely as possible using the correct units for each field. Check that you have selected the right unit (e.g. kilograms vs pounds, meters vs feet) before calculating. Rounding inputs early can reduce output precision.
Does Atom Economy Calculator work offline?
Once the page is loaded, the calculation logic runs entirely in your browser. If you have already opened the page, most calculators will continue to work even if your internet connection is lost, since no server requests are needed for computation.
What formula does Atom Economy Calculator use?
The formula used is described in the Formula section on this page. It is based on widely accepted standards in the relevant field. If you need a specific reference or citation, the References section provides links to authoritative sources.