{"id":66857,"date":"2026-10-13T09:53:31","date_gmt":"2026-10-13T06:53:31","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66857"},"modified":"2026-10-13T09:53:31","modified_gmt":"2026-10-13T06:53:31","slug":"centor-score-calculator","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/medical\/centor-score-calculator\/","title":{"rendered":"Centor Score 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\">Assess Strep Throat Risk with the Modified Centor Criteria<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66857\" data-favorite-title=\"Centor Score\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/medical\/centor-score-calculator\/\" data-favorite-excerpt=\"Enter the patient&#039;s age and four clinical signs to compute the modified Centor (McIsaac) score and see the estimated risk of group A strep throat, with guidance on testing and treatment.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-flask\">\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\/medical\/centor-score-calculator\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66857\" data-post=\"66857\"><fieldset class=\"fieldset-input is-1\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field has-term\" id=\"input-1\"><label for=\"field-1\">Age<\/label><div class=\"term\">Age<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"text\" name=\"age\" id=\"field-1\" aria-describedby=\"calc-unit-1 calc-info-1\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 25\" min=\"0\" max=\"120\" value=\"25\"\/><div class=\"unit\" id=\"calc-unit-1\">years<\/div><small id=\"calc-info-1\">Age adjusts the score: 3\u201314 years adds 1 point, 45+ subtracts 1 point<\/small><\/div><div class=\"field is-checkbox\" id=\"input-2\"><input type=\"checkbox\" id=\"field-2\" value=\"1\" checked=\"checked\"\/><label for=\"field-2\">Tonsillar exudates or swelling<\/label><\/div><div class=\"field is-checkbox\" id=\"input-3\"><input type=\"checkbox\" id=\"field-3\" value=\"1\" checked=\"checked\"\/><label for=\"field-3\">Tender anterior cervical lymph nodes<\/label><\/div><div class=\"field is-checkbox\" id=\"input-4\"><input type=\"checkbox\" id=\"field-4\" value=\"1\" checked=\"checked\"\/><label for=\"field-4\">Fever (temperature above 38 \u00b0C \/ 100.4 \u00b0F)<\/label><\/div><div class=\"field is-checkbox\" id=\"input-5\"><input type=\"checkbox\" id=\"field-5\" value=\"1\" checked=\"checked\"\/><label for=\"field-5\">Absence of cough<\/label><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66857\">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 Modified Centor Score<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Modified Centor score (McIsaac)<\/span><span class=\"result-term\">Score<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"points\"><\/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>Strep throat risk category<\/span><span class=\"result-term\">Risk<\/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 is-column\" id=\"output-3\"><span class=\"field-title\"><span>What your score means<\/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=\"66857\" 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>Modified Centor Score 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{Score} = [\\text{tonsillar exudates or swelling}] + [\\text{tender anterior cervical nodes}] + [\\text{fever} &gt; 38\\,^\\circ\\mathrm{C}] + [\\text{absence of cough}] + A\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>Each clinical criterion counts 1 point if present and 0 if absent (the bracket notation means \\(1\\) when the criterion is true, \\(0\\) when it is false).<\/li>\n<li>\\(A\\) \u2014 age adjustment: \\(+1\\) for ages 3\u201314 years, \\(0\\) for ages 15\u201344 years, \\(-1\\) for age 45 and older.<\/li>\n<\/ul>\n<p>The total ranges from \\(-1\\) to \\(5\\) and estimates the probability that a sore throat is caused by group A <em>Streptococcus<\/em> (strep throat) rather than a virus. This is the modified version published by McIsaac in 1998; the original Centor score from 1981 used only the four clinical criteria without the age adjustment.<\/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>Modified Centor Score \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> a 25-year-old patient has a sore throat with visibly swollen tonsils covered in exudate, tender enlarged lymph nodes at the front of the neck, a temperature of 38.5 \u00b0C, and no cough.<\/p>\n<p>\\[ \\text{Score} = 1 + 1 + 1 + 1 + 0 = 4 \\]<\/p>\n<p>The age adjustment is \\(0\\) because the patient is between 15 and 44 years old.<\/p>\n<p><strong>Result:<\/strong> 4 points \u2014 a very high risk category, with roughly a 51\u201353% probability of group A strep pharyngitis. A rapid strep test or throat culture is recommended, and many guidelines permit empiric antibiotic treatment at this level.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>Enter the patient's age in years in the <strong>Age<\/strong> field. Age is scored automatically: 3\u201314 years adds 1 point, 45 years and older subtracts 1 point, and 15\u201344 years adds nothing.<\/li>\n<li>Tick <strong>Tonsillar exudates or swelling<\/strong> if the tonsils show visible pus or marked swelling.<\/li>\n<li>Tick <strong>Tender anterior cervical lymph nodes<\/strong> if the \u201cglands\u201d at the front of the neck are enlarged and painful to touch.<\/li>\n<li>Tick <strong>Fever (temperature above 38 \u00b0C \/ 100.4 \u00b0F)<\/strong> if a fever was measured or reported in the last 24 hours.<\/li>\n<li>Tick <strong>Absence of cough<\/strong> if the patient is not coughing \u2014 a cough makes a viral cause more likely.<\/li>\n<li>Read the result: the total score in points, the strep throat risk category, and an explanation of what the score means for testing and treatment.<\/li>\n<\/ol>\n<h2>What is the Centor score?<\/h2>\n<p>The Centor score is a clinical prediction rule that helps distinguish bacterial (streptococcal) pharyngitis from the much more common viral sore throat. Most sore throats are caused by viruses and get better on their own, but group A <em>Streptococcus<\/em> (GAS) infections benefit from antibiotic treatment \u2014 both to shorten the illness and to prevent serious complications such as rheumatic fever and kidney inflammation. The score turns five easily observed findings into a single number that estimates the chance the infection is bacterial.<\/p>\n<p>The four original Centor criteria \u2014 tonsillar exudates, tender anterior cervical lymph nodes, fever, and absence of cough \u2014 were joined by an age adjustment in the McIsaac modification. This reflects real epidemiology: strep throat is most common in school-age children aged 3\u201314 and uncommon in adults over 45, so age shifts the probability up or down by one point.<\/p>\n<p>The result should be read as a probability estimate, not a diagnosis. As the score rises, so does the likelihood of strep: a score of 0 or below corresponds to roughly a 1\u20132.5% chance, a score of 2 to about 11\u201317%, and a score of 4 or 5 to roughly 51\u201353%. Guidelines typically use these bands to decide whether to test, treat, or simply reassure \u2014 the exact cut-off varies between countries and depends on local strep prevalence.<\/p>\n<h2>Interpreting the score: reference table<\/h2>\n<table>\n<thead>\n<tr>\n<th>Score<\/th>\n<th>Approximate strep probability<\/th>\n<th>Typical recommendation<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u22121 to 0<\/td>\n<td>1\u20132.5%<\/td>\n<td>No testing, no antibiotics \u2014 viral cause most likely<\/td>\n<\/tr>\n<tr>\n<td>1<\/td>\n<td>5\u201310%<\/td>\n<td>Testing usually not needed unless other risk factors exist<\/td>\n<\/tr>\n<tr>\n<td>2<\/td>\n<td>11\u201317%<\/td>\n<td>Rapid strep test or throat culture; treat only if positive<\/td>\n<\/tr>\n<tr>\n<td>3<\/td>\n<td>28\u201335%<\/td>\n<td>Test recommended; some clinicians treat empirically<\/td>\n<\/tr>\n<tr>\n<td>4\u20135<\/td>\n<td>51\u201353%<\/td>\n<td>Empiric treatment or confirmatory testing per local practice<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<h2>Limitations and practical tips<\/h2>\n<ul>\n<li><strong>The score cannot confirm strep throat.<\/strong> Only a rapid antigen test, throat culture, or a clinician's assessment can do that. The score tells you whether testing is worthwhile, not what the test will show.<\/li>\n<li><strong>The risk percentages are population estimates<\/strong> from validation studies. Individual probability depends on local strep prevalence, season, and recent contact with a confirmed case \u2014 during outbreaks, a given score means a higher risk.<\/li>\n<li><strong>Not validated under age 3.<\/strong> Group A strep pharyngitis is rare in children under 3 years; the calculator flags this, and interpretation requires clinical judgement.<\/li>\n<li><strong>Treat the patient, not the score.<\/strong> Other findings \u2014 for example a viral rash, oral ulcers, or a severe systemic illness \u2014 can override the score. Suspected peritonsillar abscess, difficulty breathing, or drooling need urgent medical attention regardless of the score.<\/li>\n<li><strong>Don't treat a positive-looking score blindly.<\/strong> Overtreatment with antibiotics causes side effects and resistance; most guidelines prefer confirmation by test before prescribing.<\/li>\n<\/ul>\n<p>If you're assessing other acute conditions, you may also find the <a href=\"https:\/\/wpcalc.com\/en\/medical\/qsofa-score-calculator\/\">qSOFA Score<\/a> for suspected infection, the <a href=\"https:\/\/wpcalc.com\/en\/medical\/curb-65-score-calculator\/\">CURB-65 Score<\/a> for pneumonia severity, or the <a href=\"https:\/\/wpcalc.com\/en\/medical\/heart-score-calculator\/\">HEART Score<\/a> for chest pain useful. All of these tools, like the Centor score, are decision aids that support \u2014 but never replace \u2014 a healthcare professional's judgement.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Enter the patient's age and four clinical signs to compute the modified Centor (McIsaac) score and see the estimated risk of group A strep throat, with guidance on testing and treatment.<\/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":[8],"tags":[50],"class_list":["post-66857","post","type-post","status-publish","format-standard","hentry","category-medical","tag-diagnostics"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66857","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=66857"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66857\/revisions"}],"predecessor-version":[{"id":66858,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66857\/revisions\/66858"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66857"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66857"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66857"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}