{"id":59964,"date":"2016-12-29T11:23:57","date_gmt":"2016-12-29T09:23:57","guid":{"rendered":"https:\/\/wpcalc.com\/?p=59964"},"modified":"2026-09-30T18:13:05","modified_gmt":"2026-09-30T15:13:05","slug":"concrete-slab-maximum-wall-load","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/engineering\/concrete-slab-maximum-wall-load\/","title":{"rendered":"Concrete Slab Maximum Wall Load 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\">Calculate Maximum Load Capacity of Concrete Slab<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"59964\" data-favorite-title=\"Concrete Slab Maximum Wall Load\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-slab-maximum-wall-load\/\" data-favorite-excerpt=\"Calculate the maximum wall load a concrete slab-on-grade can support (lbs\/ft). Enter the concrete compressive strength (psi), modulus of subgrade reaction (pci), and slab thickness (in).\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-engineering\">\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\/engineering\/concrete-slab-maximum-wall-load\/\" method=\"POST\" class=\"calculator\" id=\"calculator-59964\" data-post=\"59964\"><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\">Compressive strength<\/label><div class=\"term\">fc<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"compressive_strength\" id=\"field-1\" aria-describedby=\"calc-unit-1\" step=\"1\" value=\"3000\"\/><div class=\"unit\" id=\"calc-unit-1\">psi<\/div><\/div><div class=\"field has-term\" id=\"input-2\"><label for=\"field-2\">Modulus of subgrade reaction<\/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=\"number\" name=\"modulus_of_subgrade_reaction\" id=\"field-2\" aria-describedby=\"calc-unit-2\" step=\"1\" value=\"100\"\/><div class=\"unit\" id=\"calc-unit-2\">pci<\/div><\/div><div class=\"field has-term\" id=\"input-3\"><label for=\"field-3\">Thickness of slab<\/label><div class=\"term\">te<\/div>  <div class=\"absolute bottom-0 left-16 top-8 w-2 h-0.5 bg-blue-500\"><\/div><input type=\"number\" name=\"thickness_of_slab\" id=\"field-3\" aria-describedby=\"calc-unit-3\" step=\"0.1\" value=\"6\"\/><div class=\"unit\" id=\"calc-unit-3\">in<\/div><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"59964\">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>Maximum Wall Load<\/span><span class=\"result-term\">P<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"lbs\/ft\"><\/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=\"59964\" 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>Concrete Slab Maximum Wall Load 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\\[P = 9.93 \\cdot \\sqrt{f_c} \\cdot t_e^{2} \\cdot \\left( \\frac{k}{19000 \\cdot \\sqrt{f_c} \\cdot t_e^{3}} \\right)^{0.25}\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(P\\) \u2014 maximum wall load the slab can carry (lbs\/ft)<\/li>\n<li>\\(f_c\\) \u2014 compressive strength of the concrete (psi)<\/li>\n<li>\\(t_e\\) \u2014 effective slab thickness (in)<\/li>\n<li>\\(k\\) \u2014 modulus of subgrade reaction (pci)<\/li>\n<\/ul>\n<p>This formula estimates the maximum line load a slab-on-grade can support under a wall, based on the concrete's strength, the slab's thickness, and the stiffness of the soil beneath it.<\/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>Concrete Slab Maximum Wall Load \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> a 6-inch slab is cast with concrete that has a compressive strength of 3000 psi, over a subgrade with a modulus of reaction of 100 pci.<\/p>\n<p>\\[P = 9.93 \\cdot \\sqrt{3000} \\cdot 6^{2} \\cdot \\left( \\frac{100}{19000 \\cdot \\sqrt{3000} \\cdot 6^{3}} \\right)^{0.25}\\]<\/p>\n<p>\\[P = 9.93 \\cdot 54.77 \\cdot 36 \\cdot \\left( \\frac{100}{224{,}785{,}434} \\right)^{0.25} = 19{,}580 \\cdot 0.02583\\]<\/p>\n<p><strong>Result:<\/strong> \\(P \\approx 506\\) lbs\/ft \u2014 the slab can safely support a wall load of about 506 pounds per linear foot.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to Use the Calculator<\/h2>\n<ol>\n<li>Enter the <strong>Compressive strength<\/strong> of your concrete in psi (typical values are 2500\u20134000 psi for residential slabs).<\/li>\n<li>Enter the <strong>Modulus of subgrade reaction<\/strong> in pci. This describes how stiff the soil beneath the slab is \u2014 common values range from about 50 pci for loose sand to 200\u2013400 pci for dense gravel or rock.<\/li>\n<li>Enter the <strong>Thickness of slab<\/strong> in inches. Use the actual (or effective) thickness, accounting for any loss from uneven subgrade.<\/li>\n<li>Read the <strong>Maximum Wall Load<\/strong> result, given in lbs\/ft of wall length.<\/li>\n<\/ol>\n<h2>What Is the Maximum Wall Load on a Slab?<\/h2>\n<p>In slab-on-grade construction, interior or partition walls are sometimes placed directly on the slab rather than on separate footings. The slab then has to transfer the wall's line load through to the soil below. How much load it can carry before cracking or excessive deflection depends on three factors: the strength of the concrete, the thickness of the slab, and the stiffness of the supporting ground.<\/p>\n<p>The formula used here is a design expression based on plate theory for a concrete slab on an elastic foundation. The term \\(\\left( k \/ (19000 \\sqrt{f_c} \\, t_e^{3}) \\right)^{0.25}\\) captures the interaction between the soil and the slab \u2014 stiffer soil (higher \\(k\\)) and a thicker slab both reduce stress concentrations under the wall, allowing a higher load. Because load capacity grows roughly with the square of thickness, even a small increase in slab thickness significantly raises the maximum wall load.<\/p>\n<p>The result is expressed in pounds per linear foot (lbs\/ft), which matches how wall loads are usually specified: a wall's weight (dead load) plus anything it carries (live load), divided by its length. If the computed maximum exceeds the actual expected wall load, the slab is adequate without a separate footing; if not, you need a thicker slab, stronger concrete, better-compacted subgrade, or a footing under the wall.<\/p>\n<h2>Assumptions, Limitations, and Practical Tips<\/h2>\n<ul>\n<li>The result is an estimate for a wall placed on a interior slab-on-grade with reasonably uniform support. It does not replace a structural engineer's design for load-bearing exterior walls, heavy equipment, or dynamic loads.<\/li>\n<li>The calculation assumes the subgrade is uniform and well compacted. Soft spots, poor drainage, or uncompacted fill can drastically reduce the real capacity.<\/li>\n<li>Concrete strength should be the specified 28-day compressive strength. If you only know the mix ratio rather than the strength, our <a href=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-mix-ratio\/\">Concrete Mix Ratio<\/a> and <a href=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-ingredients\/\">Concrete Ingredients<\/a> calculators can help you plan the mix.<\/li>\n<li>Heavily loaded walls typically require control joints, reinforced concrete, or thickened slab sections (turn-down footings) along the wall line.<\/li>\n<li>If the wall load exceeds the calculated maximum, consider increasing slab thickness first \u2014 capacity scales with roughly \\(t_e^2\\), making thickness the most efficient lever.<\/li>\n<\/ul>\n<h2>Related Calculators<\/h2>\n<ul>\n<li><a href=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-slab-maximum-length-calculator\/\">Concrete Slab Maximum Length<\/a> \u2014 check joint spacing limits for the same slab.<\/li>\n<li><a href=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-slab-pour-volume\/\">Concrete Slab Pour Volume<\/a> \u2014 estimate how much concrete the slab requires.<\/li>\n<li><a href=\"https:\/\/wpcalc.com\/en\/engineering\/maximum-floor-live-load-capacity\/\">Maximum Floor Live Load Capacity<\/a> \u2014 for loads on floor systems rather than slabs-on-grade.<\/li>\n<li><a href=\"https:\/\/wpcalc.com\/en\/engineering\/concrete-wall\/\">Concrete Wall<\/a> \u2014 estimate materials for the wall itself.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Calculate the maximum wall load a concrete slab-on-grade can support (lbs\/ft). Enter the concrete compressive strength (psi), modulus of subgrade reaction (pci), and slab thickness (in).<\/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":[4],"tags":[96],"class_list":["post-59964","post","type-post","status-publish","format-standard","hentry","category-engineering","tag-concrete"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59964","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=59964"}],"version-history":[{"count":3,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59964\/revisions"}],"predecessor-version":[{"id":65960,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/59964\/revisions\/65960"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=59964"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=59964"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=59964"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}