{"id":67185,"date":"2026-10-20T09:51:43","date_gmt":"2026-10-20T06:51:43","guid":{"rendered":"https:\/\/wpcalc.com\/en\/?p=67185"},"modified":"2026-10-20T09:51:43","modified_gmt":"2026-10-20T06:51:43","slug":"conduit-fill-calculator-nec","status":"publish","type":"post","link":"https:\/\/wpcalc.com\/en\/engineering\/conduit-fill-calculator-nec\/","title":{"rendered":"Conduit Fill Calculator (NEC)"},"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\">Check Conduit Fill for Your Wire Schedule<\/h2><\/div><div class=\"calcdash-favorite group\">\n  <button type=\"button\" class=\"favorite\" id=\"favorite\" data-favorite-id=\"67185\" data-favorite-title=\"Conduit Fill\" data-favorite-url=\"https:\/\/wpcalc.com\/en\/engineering\/conduit-fill-calculator-nec\/\" data-favorite-excerpt=\"Check NEC conduit fill for up to six groups of insulated wires. Select the conduit type and trade size, then enter each wire group\u2019s insulation, size, and quantity.\" aria-label=\"Add to Favorites\" data-favorite-icon=\"icon icon-electrical\">\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\/conduit-fill-calculator-nec\/\" method=\"POST\" class=\"calculator\" id=\"calculator-67185\" data-post=\"67185\"><fieldset class=\"fieldset-input is-3\"><legend class=\"sr-only\">Input Fields<\/legend><div class=\"field\" id=\"input-1\"><label for=\"field-1\">Conduit type<\/label><div class=\"grid grid-cols-1\"><select id=\"field-1\" name=\"conduit_type\"><option value=\"emt\" selected>EMT<\/option><option value=\"rmc\">RMC<\/option><option value=\"pvc40\">PVC Schedule 40<\/option><option value=\"pvc80\">PVC Schedule 80<\/option><option value=\"fmc\">FMC<\/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\" id=\"input-2\"><label for=\"field-2\">Trade size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-2\" name=\"trade_size\"><option value=\"s12\" selected>1\/2 in<\/option><option value=\"s34\">3\/4 in<\/option><option value=\"s1\">1 in<\/option><option value=\"s114\">1-1\/4 in<\/option><option value=\"s112\">1-1\/2 in<\/option><option value=\"s2\">2 in<\/option><option value=\"s212\">2-1\/2 in<\/option><option value=\"s3\">3 in<\/option><option value=\"s312\">3-1\/2 in<\/option><option value=\"s4\">4 in<\/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=\"is-single field\" id=\"input-3\"><span class=\"font-semibold\">Wire row 1<\/span><\/div><div class=\"field\" id=\"input-4\"><label for=\"field-4\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-4\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-5\"><label for=\"field-5\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-5\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-6\"><label for=\"field-6\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-6\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"3\"\/><\/div><div class=\"is-single field\" id=\"input-7\"><span class=\"font-semibold\">Wire row 2<\/span><\/div><div class=\"field\" id=\"input-8\"><label for=\"field-8\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-8\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-9\"><label for=\"field-9\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-9\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-10\"><label for=\"field-10\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-10\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"0\"\/><\/div><div class=\"is-single field\" id=\"input-11\"><span class=\"font-semibold\">Wire row 3<\/span><\/div><div class=\"field\" id=\"input-12\"><label for=\"field-12\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-12\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-13\"><label for=\"field-13\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-13\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-14\"><label for=\"field-14\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-14\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"0\"\/><\/div><div class=\"is-single field\" id=\"input-15\"><span class=\"font-semibold\">Wire row 4<\/span><\/div><div class=\"field\" id=\"input-16\"><label for=\"field-16\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-16\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-17\"><label for=\"field-17\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-17\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-18\"><label for=\"field-18\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-18\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"0\"\/><\/div><div class=\"is-single field\" id=\"input-19\"><span class=\"font-semibold\">Wire row 5<\/span><\/div><div class=\"field\" id=\"input-20\"><label for=\"field-20\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-20\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-21\"><label for=\"field-21\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-21\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-22\"><label for=\"field-22\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-22\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"0\"\/><\/div><div class=\"is-single field\" id=\"input-23\"><span class=\"font-semibold\">Wire row 6<\/span><\/div><div class=\"field\" id=\"input-24\"><label for=\"field-24\">Insulation<\/label><div class=\"grid grid-cols-1\"><select id=\"field-24\" name=\"insulation\"><option value=\"thhn\" selected>THHN\/THWN-2<\/option><option value=\"xhhw\">XHHW-2<\/option><option value=\"thw\">THW<\/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\" id=\"input-25\"><label for=\"field-25\">Wire size<\/label><div class=\"grid grid-cols-1\"><select id=\"field-25\" name=\"wire_size\"><option value=\"a14\">14 AWG<\/option><option value=\"a12\" selected>12 AWG<\/option><option value=\"a10\">10 AWG<\/option><option value=\"a8\">8 AWG<\/option><option value=\"a6\">6 AWG<\/option><option value=\"a4\">4 AWG<\/option><option value=\"a3\">3 AWG<\/option><option value=\"a2\">2 AWG<\/option><option value=\"a1\">1 AWG<\/option><option value=\"a1_0\">1\/0 AWG<\/option><option value=\"a2_0\">2\/0 AWG<\/option><option value=\"a3_0\">3\/0 AWG<\/option><option value=\"a4_0\">4\/0 AWG<\/option><option value=\"k250\">250 kcmil<\/option><option value=\"k300\">300 kcmil<\/option><option value=\"k350\">350 kcmil<\/option><option value=\"k400\">400 kcmil<\/option><option value=\"k500\">500 kcmil<\/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\" id=\"input-26\"><label for=\"field-26\">Quantity<\/label><input type=\"text\" name=\"quantity\" id=\"field-26\" data-number inputmode=\"decimal\" autocomplete=\"off\" spellcheck=\"false\" min=\"0\" value=\"0\"\/><\/div><\/fieldset><div class=\"buttons\"><button type=\"submit\" data-text=\"Re-Calculate\" id=\"calculate-button\" data-post=\"67185\">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> Conduit Fill Results<\/h3><div class=\"result-box\"><div class=\"field-result\" id=\"output-1\"><span class=\"field-title\"><span>Total Wire Area<\/span><\/span><span class=\"field-value\" id=\"result-1\" data-unit=\"in\u00b2\"><\/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>Conduit Internal Area<\/span><\/span><span class=\"field-value\" id=\"result-2\" data-unit=\"in\u00b2\"><\/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>Conduit Fill<\/span><\/span><span class=\"field-value\" id=\"result-3\" data-unit=\"%\"><\/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-4\"><span class=\"field-title\"><span>Maximum Allowed Fill<\/span><\/span><span class=\"field-value\" id=\"result-4\" data-unit=\"%\"><\/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-5\"><span class=\"field-title\"><span>Fill Check<\/span><\/span><span class=\"field-value\" id=\"result-5\"><\/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-6\"><span class=\"field-title\"><span>Smallest Passing Trade Size<\/span><\/span><span class=\"field-value\" id=\"result-6\"><\/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-7\"><span class=\"field-title\"><span>Maximum Identical Wires<\/span><\/span><span class=\"field-value\" id=\"result-7\" data-unit=\"wires\"><\/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-8\"><span class=\"field-title\"><span>Calculation Details<\/span><\/span><span class=\"field-value\" id=\"result-8\"><\/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=\"67185\" 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>Conduit Fill 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\\[\\begin{aligned}A_{\\mathrm{w}}&amp;=\\sum_i n_i a_i\\\\F&amp;=\\frac{A_{\\mathrm{w}}}{A_{\\mathrm{c}}}\\times100\\%\\end{aligned}\\]\n<\/div>\r\n\t<\/figure>\r\n\t<\/p>\n<p><strong>Where:<\/strong><\/p>\n<ul>\n<li>\\(A_{\\mathrm{w}}\\) \u2014 combined area of all wires (in\u00b2)<\/li>\n<li>\\(n_i\\) \u2014 quantity of wires in row \\(i\\)<\/li>\n<li>\\(a_i\\) \u2014 area of one wire in row \\(i\\), including insulation (in\u00b2)<\/li>\n<li>\\(A_{\\mathrm{c}}\\) \u2014 internal area of the selected conduit (in\u00b2)<\/li>\n<li>\\(F\\) \u2014 percentage of conduit area occupied by wires<\/li>\n<\/ul>\n<p>The calculator sums the areas of the entered insulated conductors, then divides by the conduit\u2019s internal area. It compares the result with the NEC Chapter 9, Table 1 fill limit for the total number of wires: 53% for one, 31% for two, or 40% for three or more.<\/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>Conduit Fill \u2013 Calculation Example<\/h2><\/div>\r\n\r\n<\/p>\n<p><strong>Example:<\/strong> the default entries are three 12 AWG THHN\/THWN-2 wires in 1\/2 in EMT. Each wire occupies 0.0133 in\u00b2, and the EMT internal area is 0.304 in\u00b2.<\/p>\n<p>\\[A_{\\mathrm{w}}=3(0.0133)=0.0399\\ \\mathrm{in}^2\\]<\/p>\n<p>\\[F=\\frac{0.0399}{0.304}\\times100\\%=13.13\\%\\]<\/p>\n<p><strong>Result:<\/strong> 13.13% fill is below the 40% limit, so the selected conduit passes. The smallest passing EMT trade size in the calculator is 1\/2 in; its maximum capacity for identical 12 AWG THHN\/THWN-2 wires is nine.<\/p>\n<p>\n\r\n<\/section>\n<h2>How to use the calculator<\/h2>\n<ol>\n<li>Choose <strong>Conduit type<\/strong>\u2014EMT, RMC, PVC Schedule 40, PVC Schedule 80, or FMC\u2014and select the proposed <strong>Trade size<\/strong>.<\/li>\n<li>Under <strong>Wire row 1<\/strong>, choose the wire\u2019s <strong>Insulation<\/strong> and <strong>Wire size<\/strong>, then enter its <strong>Quantity<\/strong> as a whole number.<\/li>\n<li>Use <strong>Wire row 2<\/strong> through <strong>Wire row 6<\/strong> for other insulation-and-size combinations. Leave an unused row\u2019s <strong>Quantity<\/strong> at zero. Enter at least one wire overall.<\/li>\n<li>Read <strong>Total Wire Area<\/strong>, <strong>Conduit Internal Area<\/strong>, and <strong>Conduit Fill<\/strong>. Compare the fill with <strong>Maximum Allowed Fill<\/strong> and check <strong>Fill Check<\/strong> for PASS or FAIL.<\/li>\n<li>If needed, review <strong>Smallest Passing Trade Size<\/strong> for the same conduit type. Read <strong>Maximum Identical Wires<\/strong> and <strong>Calculation Details<\/strong> to see how the separate identical-wire capacity was determined.<\/li>\n<\/ol>\n<h2>What conduit fill tells you<\/h2>\n<p>Conduit fill is the portion of a raceway\u2019s internal cross-sectional area occupied by wires. The area used for an insulated conductor includes its insulation, not just its metal core. For a mixed schedule, each row contributes its per-wire area multiplied by its quantity. The calculator adds those contributions before determining the fill percentage.<\/p>\n<p>Under the ordinary NEC Chapter 9, Table 1 limits used here, the permitted percentage depends on the <em>total number of wires<\/em>, not on the number of distinct wire sizes or rows. For example, three wires entered together in one row and three wires entered across separate rows both use the 40% limit. A PASS means the entered wire area does not exceed that limit for the selected conduit area; it is not an approval of the entire electrical installation.<\/p>\n<p><strong>Smallest Passing Trade Size<\/strong> checks the same wire schedule against the listed sizes of the selected conduit type, from 1\/2 in through 4 in. If none passes, the result says \u201cNone through 4 in.\u201d <strong>Maximum Identical Wires<\/strong> answers a different question: how many copies of the first wire row with a nonzero quantity fit in the selected conduit. It checks the one-, two-, and three-or-more-wire limits separately. It is not additional capacity available alongside a mixed schedule.<\/p>\n<h2>Assumptions and practical checks<\/h2>\n<ul>\n<li>The calculation uses built-in conduit internal areas and insulated-wire areas for the listed selections. Confirm the applicable values against the NEC edition adopted in your jurisdiction and the actual products specified for the job.<\/li>\n<li>It assumes individual insulated conductors in an ordinary raceway run. It does not evaluate multiconductor cable assemblies, bare conductors, or special fill provisions such as those that may apply to short nipples.<\/li>\n<li>Count every conductor that occupies the raceway, including insulated equipment grounding conductors. A zero-quantity row contributes no area and does not affect the wire count.<\/li>\n<li>Fill is only one design check. Conductor ampacity adjustment, temperature correction, raceway installation requirements, and pulling conditions may require separate review. If you are selecting conductors, use the <a href=\"https:\/\/wpcalc.com\/en\/engineering\/wire-gauge\/\">wire gauge calculator<\/a> as a related reference; check the circuit with the <a href=\"https:\/\/wpcalc.com\/en\/engineering\/circuit-breaker-size\/\">circuit breaker size calculator<\/a> and assess run length with the <a href=\"https:\/\/wpcalc.com\/en\/engineering\/electrical-voltage-drop\/\">voltage drop calculator<\/a>.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Check NEC conduit fill for up to six groups of insulated wires. Select the conduit type and trade size, then enter each wire group\u2019s insulation, size, and quantity.<\/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":[4],"tags":[21],"class_list":["post-67185","post","type-post","status-publish","format-standard","hentry","category-engineering","tag-electrical"],"acf":[],"_links":{"self":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/67185","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=67185"}],"version-history":[{"count":1,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/67185\/revisions"}],"predecessor-version":[{"id":67188,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/posts\/67185\/revisions\/67188"}],"wp:attachment":[{"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/media?parent=67185"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/categories?post=67185"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wpcalc.com\/en\/wp-json\/wp\/v2\/tags?post=67185"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}