{"id":66516,"date":"2026-10-06T17:41:21","date_gmt":"2026-10-06T14:41:21","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66516"},"modified":"2026-10-06T17:41:21","modified_gmt":"2026-10-06T14:41:21","slug":"atom-economy-calculator","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/chemistry\/atom-economy-calculator\/","title":{"rendered":"Atom Economy Calculator"},"content":{"rendered":"<section class=\"not-prose calculator-box\" aria-labelledby=\"calculator-title\"><div class=\"flex items-baseline sm:items-center justify-between gap-2 sm:gap-3\"><div class=\"flex flex-col sm:flex-row sm:items-center gap-2\"><span class=\"icon icon-calculator text-primary-700! text-base! dark:text-primary-300!\" aria-hidden=\"true\"><\/span><h2 id=\"calculator-title\" class=\"text-lg font-display font-bold\">Atom Economy of a Reaction<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66516\" data-favorite-title=\"Atom Economy\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/chemistry\/atom-economy-calculator\/\" data-favorite-excerpt=\"Enter the coefficients and molar masses of all reactants in the balanced equation plus the coefficient and molar mass of your desired product to get the atom economy, the by-product mass per 100 g of reactants, and an interpretation.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-chemistry-1\">\n    <span class=\"icon icon-shape-star-empty\" aria-hidden=\"true\"><\/span>\n  <\/button>\n  <div class=\"calcdash-favorite__tip\" aria-hidden=\"true\">\n   <span class=\"favorite-tooltip\" id=\"favorite-tooltip\"><\/span>\n  <\/div>\n  <span class=\"sr-only\" role=\"status\" id=\"favorite-status\"><\/span>\n<\/div><\/div><form action=\"https:\/\/wpcalc.com\/en\/chemistry\/atom-economy-calculator\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66516\" data-post=\"66516\"><fieldset class=\"fieldset-input is-1\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"is-single field\" id=\"input-1\"><span class=\"font-semibold\">Reactants of the Balanced Equation<\/span><\/div><div class=\"field\" id=\"input-2\"><label for=\"field-2\">Reactants (coefficient + molar mass)<\/label><textarea id=\"field-2\" name=\"reactants_coefficient_molar_mass\">1 110.98\n1 105.99<\/textarea><\/div><div class=\"is-single field\" id=\"input-3\"><span class=\"font-semibold\">Desired Product<\/span><\/div><div class=\"field has-term\" id=\"input-4\"><label for=\"field-4\">Product Coefficient<\/label><div class=\"term\">\u03bdp<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"product_coefficient\" id=\"field-4\" aria-describedby=\"calc-info-4\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 1\" min=\"1\" value=\"1\"\/><small id=\"calc-info-4\">Stoichiometric coefficient of the desired product in the balanced equation (e.g. 2 for 2 NaCl)<\/small><\/div><div class=\"field has-term\" id=\"input-5\"><label for=\"field-5\">Product Molar Mass<\/label><div class=\"term\">Mp<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"product_molar_mass\" id=\"field-5\" aria-describedby=\"calc-unit-5 calc-info-5\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 100.09\" min=\"0\" value=\"100.09\"\/><div class=\"unit\" id=\"calc-unit-5\">g\/mol<\/div><small id=\"calc-info-5\">Molar mass of the desired product (e.g. 100.09 g\/mol for CaCO\u2083)<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66516\">Calculate<\/button><button type=\"reset\">Reset<\/button><\/div><div class=\"field is-checkbox hidden!\" id=\"field-auto-calc\"><input type=\"checkbox\" id=\"auto-calc\"><label for=\"auto-calc\">Calculate automatically<\/label><small>If enabled, the result will update automatically when you change any value.<\/small><\/div><div class=\"fieldset-result is-hidden\" aria-labelledby=\"result-title\" aria-live=\"polite\" role=\"region\"> <h3 class=\"result-title bg-gradient-to-r from-primary-50 to-gray-50 dark:from-primary-900 dark:to-gray-800\" id=\"result-title\"><span class=\"icon icon-s-pulse\" aria-hidden=\"true\"><\/span> Atom Economy Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Atom Economy<\/span><span class=\"result-term\">AE<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"%\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result\" id=\"output-2\"><span class=\"field-title\"><span>By-Product Mass per 100 g of Reactants<\/span><\/span><span class=\"field-value\" id=\"result-2\" data-unit=\"g\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-3\"><span class=\"field-title\"><span>Interpretation<\/span><\/span><span class=\"field-value\" id=\"result-3\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><div class=\"field-result is-column\" id=\"output-4\"><span class=\"field-title\"><span>Calculation Details<\/span><\/span><span class=\"field-value\" id=\"result-4\"><\/span><button type=\"button\" class=\"copy-result\" data-tooltip=\"Copy Result\" aria-label=\"Copy Result\"><span class=\"copy-icon icon icon-document-copy\" aria-hidden=\"true\"><\/span><\/button><\/div><\/div><div class=\"result-actions\"><button type=\"button\" class=\"copy-link\"><svg viewBox=\"0 0 20 20\" fill=\"currentColor\" aria-hidden=\"true\"><path d=\"M12.232 4.232a2.5 2.5 0 0 1 3.536 3.536l-1.225 1.224a.75.75 0 0 0 1.061 1.06l1.224-1.224a4 4 0 0 0-5.656-5.656l-3 3a4 4 0 0 0 .225 5.865.75.75 0 0 0 .977-1.138 2.5 2.5 0 0 1-.142-3.667l3-3Z\"\/><path d=\"M11.603 7.963a.75.75 0 0 0-.977 1.138 2.5 2.5 0 0 1 .142 3.667l-3 3a2.5 2.5 0 0 1-3.536-3.536l1.225-1.224a.75.75 0 0 0-1.061-1.06l-1.224 1.224a4 4 0 1 0 5.656 5.656l3-3a4 4 0 0 0-.225-5.865Z\"\/><\/svg><span class=\"copy-link__text\">Copy link to this calculation<\/span><\/button><span class=\"sr-only\" role=\"status\" id=\"copy-link-status\"><\/span><\/div><\/div><a href=\"#respond\" class=\"hidden transition-opacity duration-300 opacity-0 w-50 text-sm justify-center items-center gap-2 px-4 py-2 rounded bg-gray-200 text-gray-700 hover:bg-gray-300\" id=\"leave-comment\"><span class=\"icon icon-comments\" aria-hidden=\"true\"><\/span>Leave a Comment<\/a><\/form><\/section><section id=\"calc-reactions\" class=\"not-prose hidden my-12 bg-gradient-to-r from-primary-50 to-gray-50 border border-indigo-100 rounded-xl px-6 py-4 shadow-sm\" data-post=\"66516\" aria-live=\"polite\" aria-labelledby=\"calc-reactions-title\"><p id=\"calc-reactions-title\" class=\"text-sm text-gray-500 text-center mb-2\">How did this result make you feel?<\/p><div role=\"group\" aria-labelledby=\"calc-reactions-title\" class=\"grid grid-cols-3 sm:flex sm:flex-row sm:justify-around gap-4 sm:items-center sm:flex-wrap\"><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"like\"><span class=\"reaction-count\" data-reaction-count=\"like\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude00 <\/span><span class=\"reaction-description font-medium\">Like <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"helpful\"><span class=\"reaction-count\" data-reaction-count=\"helpful\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\udca1 <\/span><span class=\"reaction-description font-medium\">Helpful <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"confused\"><span class=\"reaction-count\" data-reaction-count=\"confused\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude15 <\/span><span class=\"reaction-description font-medium\">Confused <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"disappointed\"><span class=\"reaction-count\" data-reaction-count=\"disappointed\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\ud83d\ude1e <\/span><span class=\"reaction-description font-medium\">Disappointed <\/span><\/button><button type=\"button\" aria-pressed=\"false\" class=\"reaction-btn flex flex-col items-center gap-1 text-sm text-gray-700 hover:text-primary-600 cursor-pointer transition-transform hover:scale-105\" data-reaction=\"inaccurate\"><span class=\"reaction-count\" data-reaction-count=\"inaccurate\">0<\/span><span class=\"reaction text-3xl\" aria-hidden=\"true\">\u274c <\/span><span class=\"reaction-description font-medium\">Inaccurate <\/span><\/button><\/div><div id=\"reaction-message\" class=\"hidden mt-8 rounded-md border border-primary-100 bg-white\/50 backdrop-blur-sm px-4 py-2 text-sm text-center shadow-sm\"><\/div><\/section><div class=\"calcdash-ad not-prose calcdash-ad--calc_result calcdash-ad--in-article\"><ins class=\"adsbygoogle\" style=\"display:block\" data-ad-client=\"ca-pub-1721569815777345\" data-ad-slot=\"6317458308\" data-ad-layout=\"in-article\" data-ad-format=\"fluid\"><\/ins><script>(adsbygoogle = window.adsbygoogle || []).push({});<\/script><\/div>\n<style id=\"wpcoderpro-inline-1\">.formula-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section class=\"formula-box\" aria-labelledby=\"formula-title\">\r\n\t<div id=\"formula-title\" class=\"not-prose font-display mb-4\"><span class=\"icon icon-formula\" aria-hidden=\"true\"><\/span><h2>Atom Economy Formula<\/h2><\/div>\r\n\t<figure class=\"not-prose formula\">\r\n\t\t<figcaption class=\"formula-title\">Formula<\/figcaption>\r\n\t\t<div class=\"text-base text-gray-800\" id=\"formula\">\n\\[ \\text{AE} = \\frac{\\nu_p \\times M_p}{\\sum_i \\nu_i \\times M_i} \\times 100\\% \\\\\\ \\text{By-product mass} = 100\\% - \\text{AE} \\\\text{ (g per 100 g of reactants)} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(\\nu_p\\) \u2014 stoichiometric coefficient of the desired product in the balanced equation<\/li>\n<li>\\(M_p\\) \u2014 molar mass of the desired product (g\/mol)<\/li>\n<li>\\(\\nu_i\\) \u2014 stoichiometric coefficient of reactant \\(i\\)<\/li>\n<li>\\(M_i\\) \u2014 molar mass of reactant \\(i\\) (g\/mol)<\/li>\n<\/ul>\n<p>The formula expresses what percentage of the total mass of the reactants (in their stoichiometric ratio) ends up in the desired product, assuming a 100% yield. Everything that is not part of the desired product \u2014 all by-products \u2014 is counted as waste.<\/p>\n<p>\r\n<\/section>\n<style id=\"wpcoderpro-inline-459\">.calculation-box {\r\n\tborder-bottom: none !important;\r\n}<\/style><section id=\"calculation\" class=\"calculation-box\" aria-labelledby=\"calculation-title\">\r\n\t<div id=\"calculation-title\" class=\"not-prose font-display\"><span class=\"icon icon-unordered-list\" aria-hidden=\"true\"><\/span><h2>Atom Economy \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> calcium chloride reacts with sodium carbonate to precipitate calcium carbonate (a useful filler and building material), with sodium chloride as the by-product:<\/p>\n<p>\\[ \\text{CaCl}_2 + \\text{Na}_2\\text{CO}_3 \\rightarrow \\text{CaCO}_3 \\downarrow + 2\\,\\text{NaCl} \\]<\/p>\n<p>The reactants are entered as <code>1 110.98<\/code> (CaCl\u2082) and <code>1 105.99<\/code> (Na\u2082CO\u2083); the desired product is CaCO\u2083 with coefficient 1 and molar mass 100.09 g\/mol.<\/p>\n<p>\\[ \\text{AE} = \\frac{1 \\times 100.09}{1 \\times 110.98 + 1 \\times 105.99} \\times 100\\% = \\frac{100.09}{216.97} \\times 100\\% = 46.13\\% \\]<\/p>\n<p><strong>Result:<\/strong> the atom economy is <strong>46.13%<\/strong>, meaning 53.87 g of by-products (mostly NaCl) are formed per 100 g of reactants consumed.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Atom Economy Calculator<\/h2>\n<ol>\n<li>Write the balanced chemical equation for your reaction. Only a properly balanced equation gives a meaningful atom economy.<\/li>\n<li>In the <strong>Reactants (coefficient + molar mass)<\/strong> field, list every reactant, one per line or separated by semicolons. For each, give the stoichiometric coefficient followed by the molar mass in g\/mol, e.g. <code>2 74.09<\/code>. If you enter a single number, it is read as a molar mass with coefficient 1.<\/li>\n<li>Enter the <strong>Product Coefficient<\/strong> \u2014 the number in front of the desired product in the balanced equation (e.g. 2 for 2 NaCl).<\/li>\n<li>Enter the <strong>Product Molar Mass<\/strong> in g\/mol.<\/li>\n<li>Read the results: the atom economy in %, the by-product mass per 100 g of reactants, a short interpretation, and a step-by-step calculation you can copy into a lab report or homework.<\/li>\n<\/ol>\n<h2>What Is Atom Economy?<\/h2>\n<p>Atom economy, introduced by Barry Trost in 1991, is one of the twelve principles of green chemistry. It measures how efficiently a chemical reaction converts the mass of its starting materials into the desired product. A reaction with 100% atom economy incorporates every atom of the reactants into the product \u2014 nothing is wasted. Addition reactions and molecular rearrangements can reach this ideal, while substitution reactions, eliminations, and salt-forming reactions inevitably produce stoichiometric by-products.<\/p>\n<p>The measure matters because it captures waste at the design stage of a synthesis, before anything is mixed in a flask. Two routes to the same molecule can both give a 95% yield in the lab, yet one may generate many times its own mass in unwanted salts and solvents. Choosing the route with the higher atom economy prevents that waste rather than treating it afterwards \u2014 a far cheaper and cleaner strategy than end-of-pipe disposal.<\/p>\n<p>To interpret the result: <strong>90% and above<\/strong> is excellent and typical of addition and rearrangement chemistry; <strong>60\u201390%<\/strong> is good; <strong>40\u201360%<\/strong> is moderate, with roughly half of the reactant mass becoming waste; <strong>below 40%<\/strong> is poor, and alternative routes are usually worth seeking. Note that atom economy assumes a perfect 100% yield \u2014 real mass efficiency also depends on actual yield, solvents, purifications, and reagents used in excess, none of which this metric includes.<\/p>\n<h2>Assumptions, Limitations and Tips<\/h2>\n<ul>\n<li><strong>Balanced equation required.<\/strong> The calculator checks that the product mass does not exceed the total reactant mass, but it cannot verify that the equation is chemically correct \u2014 always balance it first. If you are unsure which reactant runs out in practice, the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/limiting-reactant-calculator\/\">Limiting Reactant calculator<\/a> can help.<\/li>\n<li><strong>Stoichiometric amounts only.<\/strong> Any reactant used in excess (common with cheap reagents) is ignored here, even though it increases real waste. Solvents, catalysts, and work-up chemicals are also excluded by definition.<\/li>\n<li><strong>Theoretical, not actual.<\/strong> A reaction with an excellent atom economy but a 20% yield can be less efficient overall than a modest route run quantitatively. Use atom economy to compare routes, not to predict real mass efficiency.<\/li>\n<li><strong>Only one desired product.<\/strong> If several products are valuable, calculate the atom economy for each one separately, or sum their masses in the numerator mentally before interpreting.<\/li>\n<li><strong>Use precise molar masses.<\/strong> Small rounding of molar masses shifts the result slightly; for reporting, carry at least two decimal places, as in the example above.<\/li>\n<li>Atom economy pairs well with other metrics and tools when evaluating a reaction \u2014 for example, the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/equilibrium-constant-calculator\/\">Equilibrium Constant calculator<\/a> tells you how far a reaction proceeds, and the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/gibbs-free-energy-calculator\/\">Gibbs Free Energy calculator<\/a> whether it is thermodynamically favorable at all.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Enter the coefficients and molar masses of all reactants in the balanced equation plus the coefficient and molar mass of your desired product to get the atom economy, the by-product mass per 100 g of reactants, and an interpretation.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[54],"tags":[57],"class_list":["post-66516","post","type-post","status-publish","format-standard","hentry","category-chemistry","tag-reactions"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66516","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/users\/3168"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=66516"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66516\/revisions"}],"predecessor-version":[{"id":66517,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66516\/revisions\/66517"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66516"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66516"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66516"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}