Electrical Conduit Size Calculator Updated Guide

function computeTotalArea() let total = 0; for (let w of wires) const areaObj = wireAreas[w.size]; if (areaObj && areaObj[w.insulation]) total += areaObj[w.insulation]; else if (areaObj && areaObj["THHN"]) total += areaObj["THHN"]; else total += 0.0133; // fallback return total;

<hr> <h3>📘 Conduit Fill Reference Table (for common wires)</h3> <div style="overflow-x:auto;"> <table> <thead> <tr><th>Wire Size (AWG/kcmil)</th><th>THHN/THWN Area (in²)</th><th>XHHW Area (in²)</th><th>Trade Size 3/4" EMT (40% fill max area)</th></tr> </thead> <tbody> <tr><td>14 AWG</td><td>0.0097</td><td>0.0123</td><td>0.213 in²</td></tr> <tr><td>12 AWG</td><td>0.0133</td><td>0.0160</td><td>0.213 in²</td></tr> <tr><td>10 AWG</td><td>0.0211</td><td>0.0243</td><td>0.213 in²</td></tr> <tr><td>8 AWG</td><td>0.0366</td><td>0.0410</td><td>0.213 in²</td></tr> <tr><td>6 AWG</td><td>0.0507</td><td>0.0590</td><td>0.346 in² (1" EMT)</td></tr> <tr><td>4 AWG</td><td>0.0824</td><td>0.0937</td><td>0.598 in² (1¼" EMT)</td></tr> </tbody> </table> <p class="note" style="margin-top:8px;">⚠️ Full NEC Chapter 9 Table 4 & 5 used in calculator logic for 1/2" to 4" conduit.</p> </div> </div> electrical conduit size calculator

// Conduit internal areas (sq in) - based on NEC Table 4 for EMT, PVC40, RMC, IMC (approx values for typical sizes) const conduitAreas = "EMT": "1/2": 0.213, "3/4": 0.346, "1": 0.598, "1 1/4": 0.984, "1 1/2": 1.342, "2": 2.028, "2 1/2": 2.731, "3": 3.916, "3 1/2": 5.027, "4": 6.388 , "PVC": "1/2": 0.201, "3/4": 0.333, "1": 0.577, "1 1/4": 0.954, "1 1/2": 1.295, "2": 1.947, "2 1/2": 2.621, "3": 3.760, "3 1/2": 4.824, "4": 6.128 , "RIGID": "1/2": 0.215, "3/4": 0.347, "1": 0.602, "1 1/4": 0.990, "1 1/2": 1.350, "2": 2.038, "2 1/2": 2.743, "3": 3.930, "3 1/2": 5.043, "4": 6.405 , "IMC": "1/2": 0.214, "3/4": 0.348, "1": 0.603, "1 1/4": 0.985, "1 1/2": 1.342, "2": 2.040, "2 1/2": 2.734, "3": 3.922, "3 1/2": 5.030, "4": 6.390 ; function computeTotalArea() let total = 0; for (let