{"id":66760,"date":"2026-10-13T08:55:37","date_gmt":"2026-10-13T05:55:37","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66760"},"modified":"2026-10-13T08:55:37","modified_gmt":"2026-10-13T05:55:37","slug":"gold-karat-to-purity-converter","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/converters\/gold-karat-to-purity-converter\/","title":{"rendered":"Gold Karat to Purity 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 Karats to Gold Purity Percentage<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66760\" data-favorite-title=\"Gold Purity\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/converters\/gold-karat-to-purity-converter\/\" data-favorite-excerpt=\"Convert gold karats to purity percentage, fineness and hallmark stamp \u2014 or enter a percentage or fineness value to get the karat equivalent. Just pick your input type and enter the number.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-other\">\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\/gold-karat-to-purity-converter\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66760\" data-post=\"66760\"><fieldset class=\"fieldset-input is-1\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field\" id=\"input-1\"><label for=\"field-1\">Your input is a<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"your_input_is_a\"><option value=\"karat\" selected>Karat value (e.g. 14)<\/option><option value=\"pct\">Purity percentage (e.g. 58.5)<\/option><option value=\"fine\">Fineness (e.g. 585)<\/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\">Gold karat \/ purity value<\/label><div class=\"term\">k<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"gold_karat_purity_value\" id=\"field-2\" aria-describedby=\"calc-info-2\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 14 for 14 karat\" min=\"0\" value=\"14\"\/><small id=\"calc-info-2\">Typical karats: 9, 10, 12, 14, 18, 22, 24<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66760\">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> Gold Purity Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Gold purity<\/span><span class=\"result-term\">purity<\/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>Fineness (parts per 1000)<\/span><span class=\"result-term\">fineness<\/span><\/span><span class=\"field-value\" id=\"result-2\" data-unit=\"\u2030\"><\/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-3\"><span class=\"field-title\"><span>Karat equivalent<\/span><span class=\"result-term\">k<\/span><\/span><span class=\"field-value\" id=\"result-3\" data-unit=\"kt\"><\/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-4\"><span class=\"field-title\"><span>Millesimal hallmark stamp<\/span><span class=\"result-term\">stamp<\/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 class=\"field-result is-column\" id=\"output-5\"><span class=\"field-title\"><span>Common karat purities for comparison<\/span><span class=\"result-term\">info<\/span><\/span><span class=\"field-value\" id=\"result-5\"><\/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=\"66760\" 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>Gold Purity<\/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\\[ P = \\frac{K}{24} \\times 100 \\quad\\text{(% purity)}, \\qquad F = \\frac{K}{24} \\times 1000 \\quad\\text{(fineness)}, \\qquad K = \\frac{P}{100} \\times 24 \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(K\\) \u2014 karat value (0 to 24)<\/li>\n<li>\\(P\\) \u2014 gold purity percentage by mass<\/li>\n<li>\\(F\\) \u2014 fineness, parts of gold per thousand<\/li>\n<\/ul>\n<p>One karat means 1 part in 24 is pure gold, so 24 kt is pure gold. The three ways of expressing purity \u2014 karat, percentage and fineness \u2014 are simply different ways of writing the same fraction of gold by mass.<\/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>Gold Purity \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> you have a 14 kt gold ring and want to know its purity, fineness and hallmark stamp.<\/p>\n<p>\\[ P = \\frac{14}{24} \\times 100 = 58.33\\% \\]<\/p>\n<p>\\[ F = \\frac{14}{24} \\times 1000 = 583.3 \\]<\/p>\n<p><strong>Result:<\/strong> 14 kt gold is 58.33% pure gold, fineness 583.3, stamped as 585. The remaining 41.67% is alloy metal such as silver, copper or zinc.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Gold Purity Calculator<\/h2>\n<ol>\n<li>Open the dropdown <strong>\u201cYour input is a\u201d<\/strong> and choose what your number represents: <em>Karat value<\/em>, <em>Purity percentage<\/em> or <em>Fineness<\/em>.<\/li>\n<li>Enter the number in the <strong>\u201cGold karat \/ purity value\u201d<\/strong> field \u2014 for example 14 for 14 karat, 58.5 for a percentage, or 585 for fineness.<\/li>\n<li>Read the results: <strong>Gold purity<\/strong> in %, <strong>Fineness<\/strong> in parts per thousand, the <strong>Karat equivalent<\/strong>, and the <strong>Millesimal hallmark stamp<\/strong> you would expect on the piece.<\/li>\n<li>Check the comparison table below the results to see how your value stacks up against the common karat grades from 9 kt to 24 kt.<\/li>\n<\/ol>\n<h2>What Does Gold Purity Mean?<\/h2>\n<p>Gold purity describes how much of a metal's mass is actually gold. Pure gold is soft and easily scratched, so it is almost always mixed with other metals \u2014 typically silver, copper, zinc, nickel or palladium \u2014 to make it harder, cheaper and sometimes to change its colour. The more gold in the alloy, the higher the purity and the more the piece is worth.<\/p>\n<p>There are three common ways to express purity. The <strong>karat<\/strong> (kt) system counts parts of gold out of 24: 12 kt is half gold, 24 kt is pure. The <strong>percentage<\/strong> system states the gold content directly, so 18 kt = 75%. The <strong>fineness<\/strong> or millesimal system counts parts of gold per 1000: 18 kt = 750, 14 kt = 585. This last number is what you find stamped inside most jewellery sold in Europe and much of the world, which is why hallmark stamps like 375, 585, 750 and 916 are worth recognising.<\/p>\n<p>A higher karat number does not automatically mean \"better\". 24 kt gold is very soft and bends or scratches easily, which makes it poorly suited to rings worn every day. Most durable everyday jewellery is 14\u201318 kt, which keeps a rich colour while holding up to wear. Investment bars and coins, on the other hand, are almost always 99.9% fine gold (24 kt, stamped 999).<\/p>\n<p>When interpreting the result, remember that purity is measured <em>by mass<\/em>, not by volume. The alloy metals in lower-karat gold also change the density and colour of the piece. If you need to work with the physical properties of the metal, our <a href=\"https:\/\/wpcalc.com\/en\/converters\/density-units-converter\/\">density unit converter<\/a> can help with the units involved.<\/p>\n<h2>Assumptions, Limitations and Practical Tips<\/h2>\n<ul>\n<li><strong>Mass basis:<\/strong> the calculator assumes purity is measured by mass, which is the standard convention for gold hallmarking worldwide.<\/li>\n<li><strong>Rounding of stamps:<\/strong> millesimal hallmark stamps are normally rounded to the nearest 5 or 10, so 14 kt (583.3) is stamped 585. The calculator follows this convention.<\/li>\n<li><strong>Valid ranges:<\/strong> karats run from 0 to 24, percentage from 0 to 100, and fineness from 0 to 1000. Values outside these ranges are physically meaningless for gold alloys.<\/li>\n<li><strong>Plating is not included:<\/strong> a gold-plated or gold-filled item may carry a karat mark describing only the thin surface layer, not the whole piece. The calculator cannot detect this \u2014 only a proper hallmark or assay can.<\/li>\n<li><strong>Regional differences:<\/strong> the legal minimum to be sold as \"gold\" varies: 9 kt in the UK, 10 kt in the US, and 14 kt or higher in many countries in Asia and continental Europe. Always check local rules when buying or selling.<\/li>\n<li><strong>Colour is not purity:<\/strong> white, rose and yellow gold of the same karat contain the same gold percentage; the difference comes from the alloy metals, not the purity.<\/li>\n<\/ul>\n<p>If you are buying a gold ring, you may also find our <a href=\"https:\/\/wpcalc.com\/en\/converters\/ring-size-converter\/\">ring size converter<\/a> useful, and if you work with other \"parts per\" measurements, the <a href=\"https:\/\/wpcalc.com\/en\/converters\/ppm-to-percent-mg-l-converter\/\">PPM to percent converter<\/a> covers similar conversions for liquids and gases.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Convert gold karats to purity percentage, fineness and hallmark stamp \u2014 or enter a percentage or fineness value to get the karat equivalent. Just pick your input type and enter the number.<\/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":[3],"tags":[31],"class_list":["post-66760","post","type-post","status-publish","format-standard","hentry","category-converters","tag-other-units"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66760","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=66760"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66760\/revisions"}],"predecessor-version":[{"id":66761,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66760\/revisions\/66761"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66760"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66760"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66760"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}