{"id":66887,"date":"2026-10-13T10:06:31","date_gmt":"2026-10-13T07:06:31","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=66887"},"modified":"2026-10-13T11:51:44","modified_gmt":"2026-10-13T08:51:44","slug":"chromatography-theoretical-plates-calculator","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/chemistry\/chromatography-theoretical-plates-calculator\/","title":{"rendered":"Chromatography Theoretical Plates 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\">Column Efficiency from a Peak<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"66887\" data-favorite-title=\"Chromatography Theoretical Plates\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/chemistry\/chromatography-theoretical-plates-calculator\/\" data-favorite-excerpt=\"Calculate the number of theoretical plates (N) of a chromatographic column from a peak&#039;s retention time and width, using either the half-height (USP\/Ph. Eur.) or baseline method. Optionally enter the column length to get the plate height (HETP).\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-spectrum\">\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\/chemistry\/chromatography-theoretical-plates-calculator\/\" method=\"POST\" class=\"calculator\" id=\"calculator-66887\" data-post=\"66887\"><fieldset class=\"fieldset-input is-2\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field is-single\" id=\"input-1\"><label for=\"field-1\">Peak Width Method<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"peak_width_method\"><option value=\"half\" selected>Width at half height (w\u00bd)<\/option><option value=\"base\">Width at baseline (wb)<\/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\">Retention Time (tR)<\/label><div class=\"term\">tR<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"retention_time_tr\" id=\"field-2\" aria-describedby=\"calc-info-2\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 10\" min=\"0\" value=\"10\"\/><div class=\"grid grid-cols-1\"><select id=\"field-3\" name=\"unit\" aria-label=\"Unit\"><option value=\"min\" selected>min<\/option><option value=\"s\">s<\/option><option value=\"h\">h<\/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><small id=\"calc-info-2\">Time from injection to the peak maximum.<\/small><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-4\">Peak Width (w)<\/label><div class=\"term\">w<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"peak_width_w\" id=\"field-4\" aria-describedby=\"calc-info-4\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 0.5\" min=\"0\" value=\"0.5\"\/><div class=\"grid grid-cols-1\"><select id=\"field-5\" name=\"unit\" aria-label=\"Unit\"><option value=\"min\" selected>min<\/option><option value=\"s\">s<\/option><option value=\"h\">h<\/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><small id=\"calc-info-4\">Width at half height or at the baseline of the same peak, depending on the method selected above.<\/small><\/div><div class=\"field has-term\" id=\"input-4\"><label for=\"field-6\">Column Length (L)<\/label><div class=\"term\">L<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><div class=\"field-group\"><input type=\"text\" name=\"column_length_l\" id=\"field-6\" aria-describedby=\"calc-info-6\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" placeholder=\"e.g. 150\" min=\"0\" value=\"150\"\/><div class=\"grid grid-cols-1\"><select id=\"field-7\" name=\"unit\" aria-label=\"Unit\"><option value=\"mm\" selected>mm<\/option><option value=\"cm\">cm<\/option><option value=\"m\">m<\/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><small id=\"calc-info-6\">Optional. Used only to compute the plate height (HETP); leave empty to skip it.<\/small><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"66887\">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> Theoretical Plates and Column Efficiency<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Number of Theoretical Plates<\/span><span class=\"result-term\">N<\/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>Plate Height (HETP)<\/span><span class=\"result-term\">H<\/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>Calculation Details<\/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 class=\"field-result is-column\" id=\"output-4\"><span class=\"field-title\"><span>About Theoretical Plates<\/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><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=\"66887\" 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>Theoretical Plates 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 = 16\\left(\\frac{t_R}{w_b}\\right)^2 \\qquad \\text{or} \\qquad N = 5.54\\left(\\frac{t_R}{w_{1\/2}}\\right)^2\nt_R\n\\]<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(N\\) \u2014 number of theoretical plates (dimensionless)<\/li>\n<li>\\(t_R\\) \u2014 retention time, from injection to the peak maximum<\/li>\n<li>\\(w_b\\) \u2014 peak width at the baseline (tangent method)<\/li>\n<li>\\(w_{1\/2}\\) \u2014 peak width at half the peak height (USP \/ Ph. Eur. method)<\/li>\n<\/ul>\n<p>Both formulas express column efficiency: the more plates, the narrower the peak relative to its retention time. If the column length \\(L\\) is known, the plate height (HETP) follows as \\(H = L\/N\\).<\/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>Theoretical Plates \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> an HPLC peak has a retention time of 10.0 min and a width at half height of 0.5 min, recorded on a 150 mm column.<\/p>\n<p>\\[ N = 5.54\\left(\\frac{10.0}{0.5}\\right)^2 = 5.54 \\times 20^2 = 5.54 \\times 400 = 2216 \\text{ plates} \\]<\/p>\n<p>\\[ H = \\frac{L}{N} = \\frac{150\\ \\text{mm}}{2216} = 0.0677\\ \\text{mm} \\approx 67.7\\ \\mu\\text{m} \\]<\/p>\n<p><strong>Result:<\/strong> N = 2,216 theoretical plates; plate height H = 0.068 mm (\u2248 68 \u00b5m).<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Calculator<\/h2>\n<ol>\n<li>Select the <strong>Peak Width Method<\/strong>: \u201cWidth at half height (w\u00bd)\u201d if you measured the width at 50% of the peak height, or \u201cWidth at baseline (wb)\u201d if you used the tangent-intersection width.<\/li>\n<li>Enter the <strong>Retention Time (tR)<\/strong> of the peak and choose its unit (min, s or h).<\/li>\n<li>Enter the <strong>Peak Width (w)<\/strong> of the same peak, measured with the method selected above, and choose its unit. The units of tR and w do not have to match \u2014 both are converted before the division.<\/li>\n<li>Optionally enter the <strong>Column Length (L)<\/strong> in mm, cm or m to also obtain the plate height (HETP). Leave it empty to skip this step.<\/li>\n<li>Read the <strong>Number of Theoretical Plates (N)<\/strong>, the <strong>Plate Height (H)<\/strong> and the detailed calculation steps below the inputs.<\/li>\n<\/ol>\n<h2>What Are Theoretical Plates?<\/h2>\n<p>The number of theoretical plates \\(N\\) is the standard measure of the <em>efficiency<\/em> of a chromatographic column. The column is modelled as a stack of discrete equilibrium stages \u2014 \u201cplates\u201d \u2014 where the analyte partitions between the stationary and mobile phases. Each transfer onto a new plate adds a small, random step of band broadening; the more plates a peak passes through, the more that broadening is averaged out and the sharper the peak appears at the detector relative to its retention time.<\/p>\n<p>A high \\(N\\) means narrow peaks and good separation power. A well-packed modern HPLC column typically delivers 5,000\u201320,000 plates on a 150 mm length, corresponding to plate heights of roughly 5\u201330 \u00b5m, while long capillary GC columns can reach 10\u2075\u201310\u2076 plates. Manufacturers quote a minimum plate count in the column specification, so \\(N\\) is routinely checked when a new column is qualified and monitored as the column ages \u2014 a steady decline signals deteriorating packing, contamination or a damaged column.<\/p>\n<p>The plate height \\(H = L\/N\\) (also called HETP, height equivalent to a theoretical plate) normalises efficiency by column length: it is the length of column that behaves as one equilibrium stage. Smaller \\(H\\) means a more efficient column, and comparing \\(H\\) rather than \\(N\\) lets you judge columns of different lengths fairly. \\(H\\) depends on flow rate and particle size through the Van Deemter equation, which is why efficiency is best at an optimal velocity.<\/p>\n<p>Peak width alone is not enough to judge a column: a peak that elutes late is naturally broader. The plate count deliberately compares the width to the retention time, so \\(N\\) rewards columns that keep peaks sharp over the whole run. If you want to know whether two peaks will actually be separated, combine \\(N\\) with retention and selectivity in the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/chromatography-resolution-calculator\/\">Chromatography Resolution calculator<\/a>.<\/p>\n<h2>Choosing the Width Method<\/h2>\n<p>The <strong>half-height width<\/strong> \\(w_{1\/2}\\) is the method of the US and European Pharmacopoeias (USP, Ph. Eur.) and is what most data systems and column certificates report. It is measured at 50% of the peak height, far from the baseline, which makes it robust against baseline noise, drift and slight tailing. The <strong>baseline width<\/strong> \\(w_b\\) is the distance between the points where tangents drawn through the inflection points of the peak intersect the baseline; it is the classical textbook definition. For a perfectly Gaussian peak the two agree, because \\(w_b = 4\\sigma\\) and \\(w_{1\/2} = 2.355\\sigma\\), so \\(w_b \\approx 1.70\\,w_{1\/2}\\) \u2014 the calculator shows the equivalent plate count with the other convention so you can compare your result with literature values.<\/p>\n<p>Whichever method you use, measure \\(w\\) and \\(t_R\\) on the <em>same<\/em> peak, and always report the method alongside \\(N\\), since tailed or fronted peaks (asymmetry factor above about 1.5) give noticeably different plate counts with the two conventions.<\/p>\n<h2>Assumptions, Limitations and Tips<\/h2>\n<ul>\n<li><strong>Gaussian peak:<\/strong> both formulas assume an approximately symmetrical, Gaussian peak. Strong tailing (common with basic analytes on silica columns) inflates \\(w_b\\) more than \\(w_{1\/2}\\), so the half-height method is the safer choice for imperfect peaks.<\/li>\n<li><strong>Negligible extra-column broadening:<\/strong> the calculation attributes all broadening to the column. Excessive tubing volume, a poorly cut ferrule, a large detector cell or a slow data-sampling rate all broaden the peak and lower the measured \\(N\\).<\/li>\n<li><strong>Use a well-retained, unretained-free peak:<\/strong> plate counts are normally reported for a moderately retained marker peak; \\(N\\) increases with \\(t_R\\), so compare values measured at similar retention.<\/li>\n<li><strong>Diagnosing low values:<\/strong> if \\(N\\) is far below the column specification, check for a void at the column inlet, contamination on the guard column, incorrect flow rate or temperature, or simply an aged column. Replacing the guard or flushing the column often restores much of the lost efficiency.<\/li>\n<li><strong>Consistent units:<\/strong> the calculator converts both times to the same unit before dividing, so the ratio \\(t_R\/w\\) \u2014 and hence \\(N\\) \u2014 is dimensionless and independent of whether you work in minutes or seconds.<\/li>\n<\/ul>\n<h2>Related Concepts<\/h2>\n<p>Retention itself is governed by how the analyte distributes between the two phases; you can quantify that distribution with the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/partition-coefficient-calculator\/\">Partition Coefficient calculator<\/a>. Once you know \\(N\\), the retention factors and the selectivity of two adjacent peaks, use the <a href=\"https:\/\/wpcalc.com\/en\/chemistry\/chromatography-resolution-calculator\/\">Chromatography Resolution calculator<\/a> to predict whether the pair will be baseline-separated.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Calculate the number of theoretical plates (N) of a chromatographic column from a peak's retention time and width, using either the half-height (USP\/Ph. Eur.) or baseline method. Optionally enter the column length to get the plate height (HETP).<\/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":[54],"tags":[59],"class_list":["post-66887","post","type-post","status-publish","format-standard","hentry","category-chemistry","tag-spectrophotometry"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66887","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=66887"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66887\/revisions"}],"predecessor-version":[{"id":67083,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/66887\/revisions\/67083"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=66887"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=66887"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=66887"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}