{"id":55898,"date":"2015-10-24T15:55:09","date_gmt":"2015-10-24T13:55:09","guid":{"rendered":"http:\/\/wpcalc.com\/?p=55898"},"modified":"2026-09-28T09:37:45","modified_gmt":"2026-09-28T06:37:45","slug":"surface-current-density","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/converters\/surface-current-density\/","title":{"rendered":"Surface Current Density 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 Surface Current Density Between Units<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"55898\" data-favorite-title=\"Surface Current Density\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/converters\/surface-current-density\/\" data-favorite-excerpt=\"Convert surface current density between A\/m, kA\/m, mA\/m, A\/cm, and the listed electrostatic CGS unit. Enter a value and select the units to convert from and to.\" 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\/surface-current-density\/\" method=\"POST\" class=\"calculator\" id=\"calculator-55898\" data-post=\"55898\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Surface current density<\/label><input type=\"text\" name=\"surface_current_density\" id=\"field-1\" aria-describedby=\"calc-unit-1 calc-info-1\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"10\"\/><div class=\"unit\" id=\"calc-unit-1\"><\/div><small id=\"calc-info-1\">Enter the surface current density value to convert<\/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=\"A\/m\">Ampere per meter (A\/m)<\/option><option value=\"kA\/m\">Kiloampere per meter (kA\/m)<\/option><option value=\"mA\/m\">Milliampere per meter (mA\/m)<\/option><option value=\"A\/cm\">Ampere per centimeter (A\/cm)<\/option><option value=\"esu\/s\u00b7cm\">Statampere per second per centimeter (esu\/s\u00b7cm)<\/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=\"A\/m\">Ampere per meter (A\/m)<\/option><option value=\"kA\/m\">Kiloampere per meter (kA\/m)<\/option><option value=\"mA\/m\">Milliampere per meter (mA\/m)<\/option><option value=\"A\/cm\">Ampere per centimeter (A\/cm)<\/option><option value=\"esu\/s\u00b7cm\">Statampere per second per centimeter (esu\/s\u00b7cm)<\/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=\"55898\">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 Surface Current Density<\/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=\"55898\" 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>Surface Current Density 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\\[K_{\\mathrm{to}}=K_{\\mathrm{from}}\\frac{f_{\\mathrm{from}}}{f_{\\mathrm{to}}}\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(K_{\\mathrm{from}}\\) \u2014 the entered surface current density.<\/li>\n<li>\\(K_{\\mathrm{to}}\\) \u2014 the converted value.<\/li>\n<li>\\(f_{\\mathrm{from}}\\) and \\(f_{\\mathrm{to}}\\) \u2014 the selected units\u2019 conversion factors to A\/m.<\/li>\n<\/ul>\n<p>The calculator first converts the entered value to A\/m, then divides by the target unit\u2019s factor. Its factors are 1 for A\/m, 1,000 for kA\/m, 0.001 for mA\/m, and 100 for A\/cm. The listed CGS unit requires special care because its calculator factor is incorrect; see the limitations 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>Surface Current Density \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> convert the default value of 10 A\/m to A\/cm. Since 1 A\/cm equals 100 A\/m, divide by 100.<\/p>\n<p>\\[10\\ \\mathrm{A\/m}\\times\\frac{1\\ \\mathrm{A\/cm}}{100\\ \\mathrm{A\/m}}=0.1\\ \\mathrm{A\/cm}\\]<\/p>\n<p><strong>Result:<\/strong> 10 A\/m = 0.1 A\/cm.<\/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>Surface current density<\/strong>. The default is 10.<\/li>\n<li>Choose the unit of that number under <strong>From unit<\/strong>. The default is A\/m.<\/li>\n<li>Choose the desired <strong>To unit<\/strong>. The default is A\/cm.<\/li>\n<li>Read <strong>Converted Surface Current Density<\/strong>. With the defaults, the result is 0.1 A\/cm.<\/li>\n<\/ol>\n<p>If you are comparing measurements, check that both values describe current per unit width along a surface. Changing units does not change the physical current distribution; it only changes how its magnitude is expressed.<\/p>\n<h2>What surface current density means<\/h2>\n<p>Surface current density describes electric current flowing along a surface per unit width measured across the flow. It is commonly denoted by \\(K\\) and measured in amperes per meter (A\/m). For example, if 10 A flows uniformly across a 2 m-wide strip, its surface current density is 5 A\/m. That simple division assumes the current is distributed uniformly across the width.<\/p>\n<p>The quantity is useful when a current is modeled as confined to a thin conducting sheet or to the surface of a conductor. In electromagnetism, a surface current can also appear in boundary conditions: a sheet of current is associated with a change in the tangential magnetic field across the sheet. Antenna and high-frequency models may use surface current density to describe how current varies over a conductor\u2019s surface.<\/p>\n<p>Surface current density is not the same as total <a href=\"https:\/\/wpcalc.com\/en\/converters\/electric-current\/\">electric current<\/a>, which is measured in amperes. A value in A\/m describes current relative to a width; finding total current requires information about the current distribution across that width. It is also distinct from magnetic flux density, even though both quantities can be important in an electromagnetic model. Use the <a href=\"https:\/\/wpcalc.com\/en\/converters\/magnetic-flux-density\/\">magnetic flux density converter<\/a> when the quantity you have is expressed in teslas or another magnetic-flux-density unit.<\/p>\n<h2>Units and conversion factors<\/h2>\n<p>For the four metric choices, each factor below gives the number of A\/m in one unit. The CGS row shows the factor used by this calculator, not the physically correct conversion.<\/p>\n<table>\n<thead>\n<tr>\n<th>Unit<\/th>\n<th>Factor to A\/m<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>A\/m<\/td>\n<td>1<\/td>\n<\/tr>\n<tr>\n<td>kA\/m<\/td>\n<td>1,000<\/td>\n<\/tr>\n<tr>\n<td>mA\/m<\/td>\n<td>0.001<\/td>\n<\/tr>\n<tr>\n<td>A\/cm<\/td>\n<td>100<\/td>\n<\/tr>\n<tr>\n<td>esu\/s\u00b7cm, as calculated by this tool<\/td>\n<td>0.0000333564<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>For instance, 1 A\/cm equals 100 A\/m because one centimeter is one-hundredth of a meter. Conversely, 1 A\/m equals 0.01 A\/cm. The available metric choices cover both larger and smaller numerical values without changing the underlying quantity.<\/p>\n<h2>Assumptions and limitations<\/h2>\n<p><strong>Important CGS unit warning:<\/strong> the calculator labels one choice \u201cesu\/s\u00b7cm,\u201d corresponding to statamperes per centimeter if read as esu\/(s\u00b7cm). Its code uses 0.0000333564 A\/m per statA\/cm. The physically correct conversion is approximately \\(1\\ \\mathrm{statA\/cm}=3.33564\\times10^{-8}\\ \\mathrm{A\/m}\\). The calculator\u2019s factor is 1,000 times too large, so results involving that choice should not be used as physical unit conversions. Conversions among A\/m, kA\/m, mA\/m, and A\/cm use the correct factors.<\/p>\n<p>This tool converts units; it does not calculate surface current density from a current measurement or determine how current varies across a conductor. The uniform-strip example above is only a way to interpret A\/m. For a nonuniform current distribution, the local surface current density depends on position, and a single converted number cannot describe the entire surface. The input also accepts only nonnegative values, so it cannot represent a signed current component or direction.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Convert surface current density between A\/m, kA\/m, mA\/m, A\/cm, and the listed electrostatic CGS unit. Enter a value and select the units to convert from and to.<\/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-55898","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\/55898","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=55898"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/55898\/revisions"}],"predecessor-version":[{"id":65314,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/55898\/revisions\/65314"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=55898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=55898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=55898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}