{"id":65421,"date":"2026-09-28T18:25:48","date_gmt":"2026-09-28T15:25:48","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=65421"},"modified":"2026-09-29T15:19:21","modified_gmt":"2026-09-29T12:19:21","slug":"roman-numerals-converter","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/converters\/roman-numerals-converter\/","title":{"rendered":"Roman Numerals 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 to and from Roman Numerals<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"65421\" data-favorite-title=\"Roman Numerals\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/converters\/roman-numerals-converter\/\" data-favorite-excerpt=\"Convert any whole number from 1 to 3999 into its Roman numeral, or translate a Roman numeral back into an Arabic number. Just pick the direction, type your value, and get the result instantly.\" 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\/roman-numerals-converter\/\" method=\"POST\" class=\"calculator\" id=\"calculator-65421\" data-post=\"65421\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Conversion direction<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"conversion_direction\"><option value=\"to_roman\" selected>Number \u2192 Roman numeral<\/option><option value=\"to_number\">Roman numeral \u2192 Number<\/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\">Number<\/label><div class=\"term\">n<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"number\" id=\"field-2\" aria-describedby=\"calc-info-2\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"1\" max=\"3999\" value=\"2024\"\/><small id=\"calc-info-2\">Whole number from 1 to 3999 (the standard Roman numerals range)<\/small><\/div><div class=\"field has-term\" id=\"input-3\" hidden><label for=\"field-3\">Roman numeral<\/label><div class=\"term\">R<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"roman_numeral\" id=\"field-3\" aria-describedby=\"calc-info-3\" placeholder=\"e.g. MMXXIV\" step=\"any\" value=\"MMXXIV\"\/><small id=\"calc-info-3\">Use the letters I, V, X, L, C, D, M \u2014 case does not matter<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"65421\">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 is-column\" id=\"output-1\"><span class=\"field-title\"><span>Roman numeral<\/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 is-column\" id=\"output-2\"><span class=\"field-title\"><span>Arabic number<\/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><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=\"65421\" 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>Roman Numerals 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{Number} \\to \\text{Roman (greedy): while } n &gt; 0,\\ \\text{emit the largest symbol value } v \\le n \\text{ from } \\{1000,\\,900,\\,500,\\,400,\\,100,\\,90,\\,50,\\,40,\\,10,\\,9,\\,5,\\,4,\\,1\\},\\ \\text{then set } n \\leftarrow n - v \\\\ \\text{Roman} \\to \\text{number: } n = \\sum_{i=1}^{k} \\sigma_i, \\qquad \\sigma_i = \\begin{cases} -\\mathrm{val}(r_i), &amp; \\mathrm{val}(r_i) &lt; \\mathrm{val}(r_{i+1}) \\\\ \\mathrm{val}(r_i), &amp; \\text{otherwise} \\end{cases} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(n\\) \u2014 the Arabic number to convert (whole number from 1 to 3999)<\/li>\n<li>\\(v\\) \u2014 one of the thirteen symbol values of the standard system (1000, 900, 500, 400, \u2026, 1)<\/li>\n<li>\\(r_i\\) \u2014 the \\(i\\)-th letter of the Roman numeral, read left to right<\/li>\n<li>\\(\\mathrm{val}\\) \u2014 the value of a letter: I = 1, V = 5, X = 10, L = 50, C = 100, D = 500, M = 1000<\/li>\n<\/ul>\n<p>The first rule builds the numeral greedily, always taking the largest possible symbol; the second reads a numeral back by adding each letter's value, except when a smaller letter precedes a larger one, in which case it is subtracted (the subtractive pairs IV, IX, XL, XC, CD, CM).<\/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>Roman Numerals \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> convert the number 2024 to a Roman numeral (the default direction and value of the calculator).<\/p>\n<p>\\[ 2024 = 1000 + 1000 + 24 \\to \\mathrm{MM}, \\qquad 24 = 10 + 10 + 4 \\to \\mathrm{XX} + \\mathrm{IV} \\]<\/p>\n<p><strong>Result:<\/strong> 2024 = MMXXIV<\/p>\n<p>Reading it back with the subtractive rule confirms it: \\(M + M + X + X + IV = 1000 + 1000 + 10 + 10 + 4 = 2024\\).<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Calculator<\/h2>\n<ol>\n<li>Open the <strong>Conversion direction<\/strong> dropdown and choose <em>Number \u2192 Roman numeral<\/em> or <em>Roman numeral \u2192 Number<\/em>. The input field switches automatically.<\/li>\n<li>For <em>Number \u2192 Roman numeral<\/em>, enter a whole number between 1 and 3999 in the <strong>Number<\/strong> field.<\/li>\n<li>For the reverse direction, type the numeral in the <strong>Roman numeral<\/strong> field using the letters I, V, X, L, C, D, M. Upper or lower case both work \u2014 <code>mmxxiv<\/code> and <code>MMXXIV<\/code> are the same.<\/li>\n<li>Read the answer in the <strong>Your Results<\/strong> panel: either the <em>Roman numeral<\/em> or the <em>Arabic number<\/em>. If the input is out of range or not a valid numeral, an error message tells you exactly what to fix.<\/li>\n<\/ol>\n<h2>What Are Roman Numerals?<\/h2>\n<p>Roman numerals are the number notation of ancient Rome, built from seven capital letters: I, V, X, L, C, D and M. The system has no zero and no place value \u2014 a numeral is simply the sum of its letters, so VI is 5 + 1 = 6. Despite its age, it is still used everywhere today: clock faces, book chapters and volume numbers, film sequels and credits, monarchs and popes (Elizabeth II), Super Bowl numbering, and cornerstone dates on buildings.<\/p>\n<p>The one non-obvious rule is <em>subtractive notation<\/em>: when a smaller letter stands directly before a larger one, it is subtracted rather than added. That gives exactly six allowed pairs \u2014 IV = 4, IX = 9, XL = 40, XC = 90, CD = 400, CM = 900 \u2014 and it is what keeps numerals compact. Without it, 1944 would be MDCCCCXXXXIIII; with it, the numeral is the much shorter MCMXLIV.<\/p>\n<p>A correct, canonical numeral is always written from the largest value down to the smallest, with each subtractive pair kept together. When you convert a number with this calculator, the result always follows that canonical form; when you type a numeral in, it is validated against the same strict rules, so an entry like IIII or VV is rejected rather than silently misread.<\/p>\n<h2>Symbol Reference Table<\/h2>\n<table>\n<thead>\n<tr>\n<th>Symbol<\/th>\n<th>Value<\/th>\n<th>Symbol<\/th>\n<th>Value<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>I<\/td>\n<td>1<\/td>\n<td>C<\/td>\n<td>100<\/td>\n<\/tr>\n<tr>\n<td>V<\/td>\n<td>5<\/td>\n<td>D<\/td>\n<td>500<\/td>\n<\/tr>\n<tr>\n<td>X<\/td>\n<td>10<\/td>\n<td>M<\/td>\n<td>1000<\/td>\n<\/tr>\n<tr>\n<td>L<\/td>\n<td>50<\/td>\n<td>\u2014<\/td>\n<td>\u2014<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>The subtractive pairs and their values:<\/p>\n<ul>\n<li>IV = 4, IX = 9<\/li>\n<li>XL = 40, XC = 90<\/li>\n<li>CD = 400, CM = 900<\/li>\n<\/ul>\n<h2>Assumptions, Limits and Practical Tips<\/h2>\n<p>The calculator covers the <strong>standard range 1 to 3999<\/strong>, which is the range expressible with the seven basic letters under the canonical rules. Numbers of 4000 and above historically required an overline (vinculum) that multiplies a symbol by 1000 \u2014 that notation is not supported here. There is also no zero: the concept simply did not exist in the Roman system.<\/p>\n<p>Validation is strict on purpose. Forms that appear on old inscriptions or clock faces \u2014 such as IIII for 4, or repeated subtractions like IXIX \u2014 are not canonical and will produce an error message rather than a wrong number. If you get one, check the letters and their order: values must decrease left to right, and only the six subtractive pairs may \"go backwards\".<\/p>\n<p>A quick sanity check for long numerals: M repeats at most three times (MMM = 3000 is the ceiling), and the total length of a well-formed numeral never exceeds 15 characters (MMMDCCCLXXXVIII = 3888). If your input looks far longer than that, something is off.<\/p>\n<p>If you need conversions between modern notations and units instead \u2014 minutes to hours, metric prefixes, or temperature scales \u2014 try our <a href=\"https:\/\/wpcalc.com\/en\/converters\/time-units-converter\/\">Time Converter<\/a>, the <a href=\"https:\/\/wpcalc.com\/en\/converters\/metric-prefix\/\">Metric Prefix Converter<\/a> or the <a href=\"https:\/\/wpcalc.com\/en\/converters\/fahrenheit\/\">Fahrenheit to Celsius converter<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Convert any whole number from 1 to 3999 into its Roman numeral, or translate a Roman numeral back into an Arabic number. Just pick the direction, type your value, and get the result instantly.<\/p>\n","protected":false},"author":3168,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[3],"tags":[31],"class_list":["post-65421","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\/65421","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=65421"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/65421\/revisions"}],"predecessor-version":[{"id":65718,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/65421\/revisions\/65718"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=65421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=65421"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=65421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}