{"id":55908,"date":"2015-10-24T15:55:14","date_gmt":"2015-10-24T13:55:14","guid":{"rendered":"http:\/\/wpcalc.com\/?p=55908"},"modified":"2026-09-28T09:39:10","modified_gmt":"2026-09-28T06:39:10","slug":"thermal-expansion","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/converters\/thermal-expansion\/","title":{"rendered":"Thermal Expansion Converter"},"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\">Convert Thermal Expansion Coefficients Between Units<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"55908\" data-favorite-title=\"Thermal Expansion\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/converters\/thermal-expansion\/\" data-favorite-excerpt=\"Convert a coefficient of linear thermal expansion between 1\/\u00b0C, 1\/K, \u00b5m\/m\u00b7\u00b0C, and in\/in\u00b7\u00b0F. Enter a value and select the From unit and To unit. Note: the current calculator gives incorrect results for some unit pairs.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-physic\">\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\/converters\/thermal-expansion\/\" method=\"POST\" class=\"calculator\" id=\"calculator-55908\" data-post=\"55908\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Expansion coefficient value<\/label><input type=\"text\" name=\"expansion_coefficient_value\" id=\"field-1\" aria-describedby=\"calc-unit-1 calc-info-1\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"1\"\/><div class=\"unit\" id=\"calc-unit-1\"><\/div><small id=\"calc-info-1\">Enter the linear thermal expansion coefficient value<\/small><\/div><div class=\"field\" id=\"input-2\"><label for=\"field-2\">From unit<\/label><div class=\"grid grid-cols-1\"><select id=\"field-2\" name=\"from_unit\"><option value=\"1\">Per degree Celsius (1\/\u00b0C)<\/option><option value=\"2\">Per Kelvin (1\/K)<\/option><option value=\"3\">Micrometer per meter per \u00b0C (\u00b5m\/m\u00b7\u00b0C)<\/option><option value=\"4\">Inch per inch per \u00b0F (in\/in\u00b7\u00b0F)<\/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\" id=\"input-3\"><label for=\"field-3\">To unit<\/label><div class=\"grid grid-cols-1\"><select id=\"field-3\" name=\"to_unit\"><option value=\"1\">Per degree Celsius (1\/\u00b0C)<\/option><option value=\"2\">Per Kelvin (1\/K)<\/option><option value=\"3\">Micrometer per meter per \u00b0C (\u00b5m\/m\u00b7\u00b0C)<\/option><option value=\"4\">Inch per inch per \u00b0F (in\/in\u00b7\u00b0F)<\/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><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"55908\">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> Your Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Converted Thermal Expansion Coefficient<\/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><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=\"55908\" 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>Thermal Expansion 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\\[\\alpha_{\\mathrm{to}}=\\alpha_{\\mathrm{from}}\\frac{s_{\\mathrm{from}}}{s_{\\mathrm{to}}}\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(\\alpha_{\\mathrm{from}}\\) \u2014 the entered coefficient of linear thermal expansion.<\/li>\n<li>\\(\\alpha_{\\mathrm{to}}\\) \u2014 the coefficient expressed in the selected destination unit.<\/li>\n<li>\\(s\\) \u2014 the value of one selected unit expressed in 1\/\u00b0C: \\(s=1\\) for 1\/\u00b0C or 1\/K, \\(s=10^{-6}\\) for \u00b5m\/m\u00b7\u00b0C, and \\(s=1.8\\) for in\/in\u00b7\u00b0F.<\/li>\n<\/ul>\n<p>This formula converts the coefficient without changing the physical expansion it describes. The current calculator does not apply these factors correctly for every unit pair; see the limitation below.<\/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>Thermal Expansion \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> convert the default value of 1 per degree Celsius to micrometers per meter per degree Celsius.<\/p>\n<p>\\[1\\,\\mathrm{\u00b0C}^{-1}\\times\\frac{1}{10^{-6}}=1{,}000{,}000\\,\\mu\\mathrm{m}\/(\\mathrm{m}\\cdot\\mathrm{\u00b0C})\\]<\/p>\n<p><strong>Result:<\/strong> the correct conversion is 1,000,000 \u00b5m\/m\u00b7\u00b0C. With these default selections, the current calculator instead displays 0.000001; that displayed value is incorrect.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>Enter a nonnegative number in <strong>Expansion coefficient value<\/strong>. Use a coefficient of linear expansion, not a measured change in length.<\/li>\n<li>Choose the value\u2019s existing unit in <strong>From unit<\/strong>.<\/li>\n<li>Choose the unit you want in <strong>To unit<\/strong>.<\/li>\n<li>Read <strong>Converted Thermal Expansion Coefficient<\/strong>. Before using a result involving \u00b5m\/m\u00b7\u00b0C or in\/in\u00b7\u00b0F, check it against the conversion relationships below: the current calculator can display an incorrect value.<\/li>\n<\/ol>\n<h2>What the thermal expansion coefficient means<\/h2>\n<p>The coefficient of linear thermal expansion describes the fractional change in a material\u2019s length for a temperature change. A coefficient of 12 \u00b5m\/m\u00b7\u00b0C means that, for approximately every 1\u00b0C rise, a freely expanding one-meter length becomes about 12 micrometers longer. The same coefficient can be written as \\(12\\times10^{-6}\\,\\mathrm{\u00b0C}^{-1}\\) or \\(12\\times10^{-6}\\,\\mathrm{K}^{-1}\\).<\/p>\n<p>Degrees Celsius and kelvins have equal-sized temperature <em>intervals<\/em>: a change of 1\u00b0C is a change of 1 K. Their coefficient values are therefore identical, even though the two temperature scales have different zero points. A temperature change of 1\u00b0F equals 5\/9\u00b0C, so the numerical coefficient per \u00b0F is 5\/9 of the coefficient per \u00b0C. The inch-per-inch part is a ratio of lengths and contributes no extra conversion factor.<\/p>\n<p>Engineers use these coefficients to estimate changes in dimensions when temperatures vary, such as the movement of a bridge joint or the fit between two components. The coefficient alone does not give a length change: you also need the original length and temperature change. Other thermal properties answer different questions. For example, <a href=\"https:\/\/wpcalc.com\/en\/converters\/thermal-conductivity\/\">thermal conductivity<\/a> concerns how readily a material conducts heat, while <a href=\"https:\/\/wpcalc.com\/en\/converters\/specific-heat\/\">specific heat<\/a> concerns the energy needed to change its temperature.<\/p>\n<h2>Conversion checks and limitations<\/h2>\n<p><strong>Important:<\/strong> the calculator\u2019s current conversion factors are reversed for \u00b5m\/m\u00b7\u00b0C and are also incorrect for in\/in\u00b7\u00b0F. Its displayed result is reliable for conversion between 1\/\u00b0C and 1\/K, or when the From unit and To unit are identical, but results involving different units outside those cases should not be used without an independent check. The worked example shows the discrepancy using the default selections.<\/p>\n<ul>\n<li>\\(1\\,\\mathrm{\u00b0C}^{-1}=1\\,\\mathrm{K}^{-1}=1{,}000{,}000\\,\\mu\\mathrm{m}\/(\\mathrm{m}\\cdot\\mathrm{\u00b0C})\\).<\/li>\n<li>\\(1\\,\\mathrm{\u00b0C}^{-1}=\\frac{5}{9}\\,\\mathrm{in}\/(\\mathrm{in}\\cdot\\mathrm{\u00b0F})\\), approximately 0.555556 in\/in\u00b7\u00b0F.<\/li>\n<li>For a known coefficient \\(\\alpha\\), a small, freely occurring length change can be estimated with \\(\\Delta L\\approx\\alpha L_0\\Delta T\\). Use compatible temperature units for \\(\\alpha\\) and \\(\\Delta T\\).<\/li>\n<\/ul>\n<p>Linear coefficients can depend on temperature, material composition, and direction within the material. The length-change estimate assumes a roughly constant coefficient over the temperature range; it does not calculate stress when expansion is restrained. If heating or cooling of the material is also relevant, the <a href=\"https:\/\/wpcalc.com\/en\/converters\/heat-transfer\/\">heat transfer<\/a> converter addresses a different quantity and does not replace a thermal expansion calculation.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Convert a coefficient of linear thermal expansion between 1\/\u00b0C, 1\/K, \u00b5m\/m\u00b7\u00b0C, and in\/in\u00b7\u00b0F. Enter a value and select the From unit and To unit. Note: the current calculator gives incorrect results for some unit pairs.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[34],"class_list":["post-55908","post","type-post","status-publish","format-standard","hentry","category-converters","tag-physics-units"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/55908","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\/70"}],"replies":[{"embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/comments?post=55908"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/55908\/revisions"}],"predecessor-version":[{"id":65317,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/55908\/revisions\/65317"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=55908"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=55908"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=55908"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}