{"id":57931,"date":"2016-03-18T09:16:09","date_gmt":"2016-03-18T07:16:09","guid":{"rendered":"http:\/\/wpcalc.com\/?p=57931"},"modified":"2026-09-28T13:53:37","modified_gmt":"2026-09-28T10:53:37","slug":"how-many-weeks-pregnant","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/pregnancy-baby\/how-many-weeks-pregnant\/","title":{"rendered":"How Many Weeks Pregnant 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\">Pregnancy Week, Due Date &amp; Countdown Calculator<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"57931\" data-favorite-title=\"How Many Weeks Pregnant Are You?\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/pregnancy-baby\/how-many-weeks-pregnant\/\" data-favorite-excerpt=\"Enter the first day of your last menstrual period and your usual cycle length to estimate how many weeks pregnant you are, your due date, and the time remaining until that date.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-embryo\">\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\/pregnancy-baby\/how-many-weeks-pregnant\/\" method=\"POST\" class=\"calculator\" id=\"calculator-57931\" data-post=\"57931\"><fieldset class=\"fieldset-input\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field\" id=\"input-1\"><label for=\"field-1\">First day of your last menstrual period<\/label><input type=\"date\" name=\"first_day_of_your_last_menstrual_period\" id=\"field-1\" step=\"any\" value=\"2026-11-12\"\/><\/div><div class=\"field\" id=\"input-2\"><label for=\"field-2\">Cycle Length<\/label><input type=\"text\" name=\"cycle_length\" id=\"field-2\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"20\" max=\"45\" value=\"28\"\/><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"57931\">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>Gestational age<\/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>Estimated Due Date<\/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\" id=\"output-3\"><span class=\"field-title\"><span>Until Due Date<\/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=\"57931\" 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\">5<\/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\">9<\/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\">4<\/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\">1<\/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>Pregnancy Week and Due Date 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\\[ A=L+(C-28)\\,\\text{days},\\qquad N=\\left\\lfloor\\frac{T-A}{1\\,\\text{day}}\\right\\rfloor,\\qquad W=\\left\\lfloor\\frac{N}{7}\\right\\rfloor,\\qquad R=N-7W,\\qquad E=A+280\\,\\text{days} \\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(L\\) \u2014 first day of the last menstrual period.<\/li>\n<li>\\(C\\) \u2014 cycle length in days.<\/li>\n<li>\\(A\\) \u2014 cycle-adjusted starting date.<\/li>\n<li>\\(T\\) \u2014 current date and time.<\/li>\n<li>\\(N\\) \u2014 completed days since the adjusted starting date.<\/li>\n<li>\\(W\\) and \\(R\\) \u2014 completed weeks and additional days of gestational age.<\/li>\n<li>\\(E\\) \u2014 estimated due date.<\/li>\n<\/ul>\n<p>The calculator shifts the starting date by the difference between your cycle length and 28 days, then counts 280 days from that adjusted date to estimate a due date. It reports gestational age as completed weeks plus remaining days.<\/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>Pregnancy Week and Due Date \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> Suppose the first day of your last menstrual period was August 3, 2026, your cycle length is 28 days, and you calculate at the start of September 28, 2026.<\/p>\n<p>\\[ A=\\text{August 3}+(28-28)\\,\\text{days}=\\text{August 3, 2026} \\]<\/p>\n<p>\\[ N=56\\,\\text{days}=8\\times7+0,\\qquad E=\\text{August 3, 2026}+280\\,\\text{days}=\\text{May 10, 2027} \\]<\/p>\n<p><strong>Result:<\/strong> Gestational age is 8 weeks, 0 days, and the estimated due date is May 10, 2027. At the start of September 28, the due date is 32 weeks away. Later that day, the calculator may display 31 weeks, 6 days remaining because it counts full 24-hour periods.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>In <strong>First day of your last menstrual period<\/strong>, select the first day of bleeding from your most recent menstrual period\u2014not the day it ended or a suspected conception date. The field initially shows today's date, so replace it with your actual date.<\/li>\n<li>In <strong>Cycle Length<\/strong>, enter your usual number of days from the first day of one period to the first day of the next. The default is 28 days; the accepted range is 20 to 45 days.<\/li>\n<li>Read <strong>Gestational age<\/strong> for completed weeks and days, <strong>Estimated Due Date<\/strong> for the projected delivery date, and <strong>Until Due Date<\/strong> for the time remaining.<\/li>\n<\/ol>\n<h2>What your pregnancy week means<\/h2>\n<p>Gestational age is the standard way to describe how far a pregnancy has progressed. It is counted from the first day of the last menstrual period, rather than from fertilization. In a typical 28-day cycle, ovulation occurs around two weeks after that date, so a gestational age of 8 weeks does not usually mean conception happened eight weeks ago.<\/p>\n<p>The result is written as completed weeks and additional days. For example, 8 weeks, 3 days means eight full weeks have passed and you are three days into the next week. This dating helps place prenatal tests, scans, and fetal development in context. If you want another way to review pregnancy dating, see the <a href=\"https:\/\/wpcalc.com\/en\/pregnancy-baby\/gestational-age\/\">Gestational Age Calculator<\/a>.<\/p>\n<p>A due date is an estimate, not an appointment for birth. This calculator starts with the conventional 40 weeks, or 280 days, and adjusts for cycle length: a 32-day cycle moves the estimated starting date and due date four days later than a 28-day cycle would. This assumes ovulation shifts with cycle length, which may not be true for every person. You can also explore due-date calculations with the <a href=\"https:\/\/wpcalc.com\/en\/pregnancy-baby\/pregnancy-due-date\/\">Pregnancy Due Date Calculator<\/a>.<\/p>\n<h2>Assumptions and practical limitations<\/h2>\n<p>Last-period dating is most useful when you know the date and your cycles are fairly regular. Bleeding that was not a menstrual period, an uncertain date, irregular cycles, recent hormonal contraception, or fertility treatment can make this estimate less suitable. Cycle length alone cannot identify the exact day of ovulation or conception. If you conceived through fertility treatment, your care team may use treatment dates instead.<\/p>\n<p>An early ultrasound may provide a different gestational age or due date. A clinician can decide which date to use for prenatal care, particularly when the last-period date and scan disagree. For information based on ultrasound measurements, see the <a href=\"https:\/\/wpcalc.com\/en\/pregnancy-baby\/ultrasound-gestation-period\/\">Ultrasound Gestation Period Calculator<\/a>. Do not change a due date recorded by your care team solely because an online estimate differs.<\/p>\n<p>The <strong>Until Due Date<\/strong> value is calculated from the current moment, while the due date is displayed as a calendar date. It can therefore look one day shorter than a simple count between calendar dates. If the estimated due date has passed, the remaining-time output may show negative weeks or days rather than an intuitive \u201coverdue\u201d label. A past due date does not, by itself, tell you when labor will begin; ask your maternity care team how your pregnancy should be monitored.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Enter the first day of your last menstrual period and your usual cycle length to estimate how many weeks pregnant you are, your due date, and the time remaining until that date.<\/p>\n","protected":false},"author":70,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[45],"tags":[47],"class_list":["post-57931","post","type-post","status-publish","format-standard","hentry","category-pregnancy-baby","tag-pregnancy-tracking"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/57931","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=57931"}],"version-history":[{"count":4,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/57931\/revisions"}],"predecessor-version":[{"id":65384,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/57931\/revisions\/65384"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=57931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=57931"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=57931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}