{"id":66895,"date":"2026-10-13T10:09:02","date_gmt":"2026-10-13T07:09:02","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66895"},"modified":"2026-10-13T10:09:02","modified_gmt":"2026-10-13T07:09:02","slug":"antoine-equation-calculator","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/chemistry\/antoine-equation-calculator\/","title":{"rendered":"Antoine Equation 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\">Find Vapor Pressure or Boiling Temperature from Antoine Coefficients<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66895\" data-favorite-title=\"Antoine Equation\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/chemistry\/antoine-equation-calculator\/\" data-favorite-excerpt=\"Calculate the vapor pressure of a pure liquid at a given temperature, or the boiling temperature at a given pressure, using Antoine coefficients A, B and C. Works with mmHg, kPa, bar and other pressure units.\" 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\/antoine-equation-calculator\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66895\" data-post=\"66895\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Solve for<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"solve_for\"><option value=\"p\" selected>Vapor pressure (from temperature)<\/option><option value=\"t\">Temperature (from pressure)<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-2\">Temperature (T)<\/label><div class=\"term\">T<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"number\" name=\"temperature_t\" id=\"field-2\" aria-describedby=\"calc-info-2\" placeholder=\"e.g. 100\" min=\"-273.15\" step=\"any\" value=\"100\"\/><div class=\"grid grid-cols-1\"><select id=\"field-3\" name=\"unit\" aria-label=\"Unit\"><option value=\"degC\" selected>\u00b0C<\/option><option value=\"K\">K<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><small id=\"calc-info-2\">Temperature of the liquid. Antoine C coefficients are almost always tabulated with T in \u00b0C; K is converted automatically.<\/small><\/div><div class=\"field has-term\" id=\"input-3\" hidden><label for=\"field-4\">Vapor Pressure (P)<\/label><div class=\"term\">P<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"vapor_pressure_p\" id=\"field-4\" aria-describedby=\"calc-info-4\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 760\" min=\"0\" value=\"760\"\/><small id=\"calc-info-4\">Pressure in the unit of the coefficient set (selected below).<\/small><\/div><div class=\"field is-single\" id=\"input-4\"><label for=\"field-5\">Pressure Unit of the Coefficients<\/label><div class=\"grid grid-cols-1\"><select id=\"field-5\" name=\"pressure_unit_of_the_coefficients\"><option value=\"mmHg\" selected>mmHg (torr)<\/option><option value=\"kPa\">kPa<\/option><option value=\"bar\">bar<\/option><option value=\"atm\">atm<\/option><option value=\"Pa\">Pa<\/option><option value=\"psi\">psi<\/option><\/select><svg class=\"pointer-events-none col-start-1 row-start-1 mr-2 size-5 self-center justify-self-end text-gray-500 sm:size-4\" viewBox=\"0 0 16 16\" fill=\"currentColor\" aria-hidden=\"true\" data-slot=\"icon\">\n              <path fill-rule=\"evenodd\" d=\"M4.22 6.22a.75.75 0 0 1 1.06 0L8 8.94l2.72-2.72a.75.75 0 1 1 1.06 1.06l-3.25 3.25a.75.75 0 0 1-1.06 0L4.22 7.28a.75.75 0 0 1 0-1.06Z\" clip-rule=\"evenodd\" \/>\n            <\/svg><\/div><\/div><div class=\"field has-term\" id=\"input-5\"><label for=\"field-6\">Coefficient A<\/label><div class=\"term\">A<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"coefficient_a\" id=\"field-6\" aria-describedby=\"calc-info-6\" placeholder=\"e.g. 8.07131\" step=\"any\" value=\"8.07131\"\/><small id=\"calc-info-6\">Intercept. Typically 8\u20139 when P is in mmHg and T in \u00b0C.<\/small><\/div><div class=\"field has-term\" id=\"input-6\"><label for=\"field-7\">Coefficient B<\/label><div class=\"term\">B<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"coefficient_b\" id=\"field-7\" aria-describedby=\"calc-info-7\" placeholder=\"e.g. 1730.63\" step=\"any\" value=\"1730.63\"\/><small id=\"calc-info-7\">Slope parameter, always positive for real compounds.<\/small><\/div><div class=\"field has-term\" id=\"input-7\"><label for=\"field-8\">Coefficient C<\/label><div class=\"term\">C<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"coefficient_c\" id=\"field-8\" aria-describedby=\"calc-info-8\" placeholder=\"e.g. 233.426\" step=\"any\" value=\"233.426\"\/><small id=\"calc-info-8\">Temperature offset, most often 230\u2013280 when T is in \u00b0C.<\/small><\/div><div class=\"field has-term\" id=\"input-8\"><label for=\"field-9\">Lower Validity Limit<\/label><div class=\"term\">Tmin<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"lower_validity_limit\" id=\"field-9\" aria-describedby=\"calc-info-9\" placeholder=\"e.g. 1\" step=\"any\" value=\"1\"\/><small id=\"calc-info-9\">Optional: lower temperature limit of the coefficient set, in the temperature unit chosen above.<\/small><\/div><div class=\"field has-term\" id=\"input-9\"><label for=\"field-10\">Upper Validity Limit<\/label><div class=\"term\">Tmax<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"upper_validity_limit\" id=\"field-10\" aria-describedby=\"calc-info-10\" placeholder=\"e.g. 100\" step=\"any\" value=\"100\"\/><small id=\"calc-info-10\">Optional: upper temperature limit of the coefficient set, in the temperature unit chosen above.<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66895\">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> Antoine Equation Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Vapor Pressure<\/span><span class=\"result-term\">P_sat<\/span><\/span><span class=\"field-value\" id=\"result-1\"><\/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>Saturation Temperature<\/span><span class=\"result-term\">T_sat<\/span><\/span><span class=\"field-value\" id=\"result-2\"><\/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>Calculation Details<\/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><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=\"66895\" 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>Antoine Equation 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\">\\[ \\log_{10} P = A - \\frac{B}{C + T} \\]\n\\[ P = 10^{\\,A - \\frac{B}{C + T}} \\qquad\\quad T = \\frac{B}{A - \\log_{10} P} - C \\]<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(P\\) \u2014 vapor pressure of the pure compound, in the unit that matches the coefficient set (often mmHg)<\/li>\n<li>\\(T\\) \u2014 temperature, almost always in \\(^\\circ\\text{C}\\) for tabulated coefficients<\/li>\n<li>\\(A\\), \\(B\\), \\(C\\) \u2014 empirical Antoine coefficients specific to each substance, pressure unit and temperature range<\/li>\n<\/ul>\n<p>The Antoine equation is an empirical correlation for the saturation vapor pressure of a pure liquid. The second form is the inverted equation, which gives the temperature at which the liquid boils at a chosen pressure.<\/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>Antoine Equation \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> water at 100 \u00b0C, using the standard coefficient set for water with P in mmHg and T in \u00b0C: A = 8.07131, B = 1730.63, C = 233.426.<\/p>\n<p>\\[ \\log_{10} P = 8.07131 - \\frac{1730.63}{233.426 + 100} = 8.07131 - 5.1906 = 2.8807 \\]<\/p>\n<p>\\[ P = 10^{2.8807} \\approx 760.1 \\ \\text{mmHg} \\approx 101.34 \\ \\text{kPa} \\]<\/p>\n<p><strong>Result:<\/strong> the vapor pressure of water at 100 \u00b0C is about 760 mmHg \u2014 exactly 1 atmosphere, which is why water boils at 100 \u00b0C at sea level.<\/p>\n<p>Inverting the equation with P = 760 mmHg confirms this:<\/p>\n<p>\\[ T = \\frac{1730.63}{8.07131 - \\log_{10}(760)} - 233.426 = \\frac{1730.63}{5.1905} - 233.426 \\approx 100.0\\ ^\\circ\\text{C} \\]<\/p>\n<p><strong>Result:<\/strong> water boils at approximately 100.0 \u00b0C when the surrounding pressure is 760 mmHg.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>Choose <strong>Solve for<\/strong>: \"Vapor pressure (from temperature)\" or \"Temperature (from pressure)\". The relevant input field appears automatically.<\/li>\n<li>Enter the <strong>Temperature (T)<\/strong> and its unit (\u00b0C or K), or the <strong>Vapor Pressure (P)<\/strong> if you are solving for the boiling temperature. A value in kelvin is converted to \u00b0C automatically.<\/li>\n<li>Select the <strong>Pressure Unit of the Coefficients<\/strong> \u2014 this is the unit for which your A, B, C values were tabulated (e.g. mmHg for most water tables), not the unit you want the answer in. The result is also converted to kPa, atm, bar and psi.<\/li>\n<li>Enter the coefficients <strong>A<\/strong>, <strong>B<\/strong> and <strong>C<\/strong> from a reliable source such as the NIST Chemistry WebBook.<\/li>\n<li>Optionally fill in the <strong>Lower<\/strong> and <strong>Upper Validity Limit<\/strong> of the coefficient set. The calculator warns you if the temperature falls outside this range, where the equation becomes an unreliable extrapolation.<\/li>\n<li>Read the <strong>Vapor Pressure<\/strong> or <strong>Saturation Temperature<\/strong> result together with the detailed step-by-step calculation.<\/li>\n<\/ol>\n<h2>What is the Antoine equation?<\/h2>\n<p>The Antoine equation is the most widely used simple correlation for the vapor pressure of pure liquids. It relates the saturation vapor pressure to temperature through three empirical coefficients fitted to experimental data. Because vapor pressure rises steeply and non-linearly with temperature, the equation uses the reciprocal of \\(C + T\\) to capture the characteristic curvature of the vapor pressure curve \u2014 a much better fit than a straight line, while remaining easy to invert by hand.<\/p>\n<p>Vapor pressure is the pressure exerted by a vapor in equilibrium with its liquid at a given temperature. It matters whenever a liquid evaporates into a closed space: a liquid boils when its vapor pressure equals the surrounding pressure, and vapor pressure also governs evaporation rates, distillation, drying and the behavior of fuel vapors. This is why the Antoine equation appears throughout chemical engineering, thermodynamics and laboratory work.<\/p>\n<p>The inverted form is just as useful. Setting \\(P\\) equal to the external pressure gives the boiling temperature at that pressure \u2014 for example the boiling point of water on a mountain, or the reflux temperature of a solvent under reduced pressure in a rotary evaporator. Chemists also use vapor pressures to predict how volatile components partition between liquid and vapor phases, a foundation of <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/raoults-law-calculator\/\">Raoult's Law<\/a> for mixtures and of distillation design.<\/p>\n<p>Note that the coefficients are not universal constants. Each substance has its own A, B and C, and they are valid only for the specific pressure unit, temperature unit and temperature range stated in the source. Mixing units \u2014 for instance using coefficients tabulated for mmHg with a pressure in kPa \u2014 is the most common mistake and can shift the result by orders of magnitude.<\/p>\n<h2>Assumptions, limitations and practical tips<\/h2>\n<ul>\n<li><strong>Pure compounds only.<\/strong> The equation describes a single substance at vapor\u2013liquid equilibrium. For mixtures, combine pure-component vapor pressures with an activity-coefficient model such as <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/raoults-law-calculator\/\">Raoult's Law<\/a>.<\/li>\n<li><strong>Limited temperature range.<\/strong> Antoine coefficients are fitted typically over a span of a few tens of degrees (the water set used here is valid from 1 \u00b0C to 100 \u00b0C). Outside that range the equation is an extrapolation and can be badly wrong, especially near the critical point, where vapor pressure behavior follows different physics. Always enter the validity limits if you know them.<\/li>\n<li><strong>Unit consistency is critical.<\/strong> A is not dimensionless in a physical sense \u2014 it absorbs the pressure unit. A set tabulated for mmHg cannot be used with kPa pressures without refitting. Typical A values are 8\u20139 for mmHg and 5\u20137 for kPa or bar sets.<\/li>\n<li><strong>Temperature is almost always in \u00b0C.<\/strong> The coefficient C (typically 230\u2013280) already contains the offset from absolute zero for Celsius tables. If your source tabulates T in kelvin, its C will be near zero \u2014 check before entering values.<\/li>\n<li><strong>Accuracy.<\/strong> Within its valid range, the Antoine equation usually reproduces experimental vapor pressures to within a few percent, which is sufficient for most engineering and laboratory estimates. For higher precision or wide temperature spans, use the Wagner or Cox equations, or the integrated <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/van-t-hoff-equation-calculator\/\">van 't Hoff equation<\/a> when you have enthalpy-of-vaporization data.<\/li>\n<li><strong>Related gas-phase calculations.<\/strong> Once you know the vapor pressure, you can estimate properties of the resulting vapor \u2014 for example its density under given conditions with the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/gas-density-calculator\/\">Gas Density Calculator<\/a> or typical molecular speeds with the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/molecular-speed-of-a-gas-calculator\/\">Molecular Speed of a Gas Calculator<\/a>.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Calculate the vapor pressure of a pure liquid at a given temperature, or the boiling temperature at a given pressure, using Antoine coefficients A, B and C. Works with mmHg, kPa, bar and other pressure units.<\/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-66895","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\/66895","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=66895"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66895\/revisions"}],"predecessor-version":[{"id":66896,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66895\/revisions\/66896"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66895"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66895"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66895"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}