WireCalc vs NEC Load Calculator

The NEC wire sizing calculator that works where you work -- even with no signal. WireCalc gives electricians, contractors, and apprentices instant access to NEC 2023 wire sizing, voltage drop calculations, and conduit fill tables. No internet required. No subscription. Just accurate answers on the job site. STOP OVERSIZING WIRE. STOP GUESSING. Enter your load and run length. Get the correct wire gauge per NEC 310.16 in seconds. Check voltage drop. Verify conduit fill. Solve Ohm's law. All based on NEC 2023 (NFPA 70) tables. FEATURES: - Wire size calculator -- sizes by both ampacity AND voltage drop per NEC - Full NEC Table 310.16 ampacity reference (interactive, searchable) - Voltage drop calculator (single-phase and three-phase) - Conduit fill calculator with NEC Chapter 9 data (EMT, IMC, RMC, PVC) - Ohm's law calculator (V, A, Ohm, W -- enter any two, get all four) - Copper and aluminum conductor support - 60°C, 75°C, and 90°C temperature ratings - THHN, THWN, XHHW, TW, THW insulation types - Pass/fail indicators with NEC-compliant thresholds WHY ELECTRICIANS CHOOSE WIRECALC: - Works 100% offline -- designed for job sites with zero signal - No subscriptions, no ads, no account required - One-time purchase -- yours forever - NEC 2023 compliant tables and calculations - Large text and tap targets -- usable with work gloves Based on NEC 2023 (NFPA 70). Note: This app is a calculation tool and reference guide. It does not replace professional judgment or code compliance verification. Always verify calculations and consult local codes and amendments.

NEC Load Calculator answers panel sizing, feeder, motor, branch circuit, and cable tray questions directly from the 2023 NEC — with the article citation and math shown for every result. Built for licensed electricians and contractors, not students. CALCULATION MODULES Residential Dwelling unit service sizing per NEC 220.40–220.55 and 220.82. Standard and optional methods. General lighting, small appliance and laundry circuits, fixed appliances, dryer, cooking equipment, HVAC, and service sizing with 230.79(C) minimums. Commercial Feeder and service load calculations per NEC 220.12, 220.44, 220.60, 430.24. Lighting, receptacles, motors, HVAC units, sign circuits, and demand factors. Supports 220/127V and 440/254V systems alongside standard US voltages, with a built-in reminder to verify against NOM-001-SEDE where applicable. Branch Circuit Conductor and OCPD sizing per NEC 210.19, 310.12, 310.15(B)(1)(a). Continuous load handling, conduit fill derating, ambient temperature correction. Covers 120V through 480V circuits, including 127V, 220V, 254V, and 440V. Motor Conductor, overload, and OCPD sizing per NEC 430.22, 430.32, 430.52. Full motor table lookups by horsepower, voltage, and phase. Panel Schedule Circuit-by-circuit panel editor with phase balance, loading percentage, and imbalance calculations per NEC 220.40 and 220.87. Cable Tray Tray fill and ampacity derating per NEC 392.22(A) and 392.80(A). Ventilated trough and solid-bottom tray types, small-cable fill-area limits, and the 90% width rule for large-cable diameter sums. RESULTS SHOW THE CALCULATION Every result includes the NEC article reference, the demand factor table used, and the step-by-step math — not just a final number. Built to be checked against the code book. PANEL LAYOUT Generate a panel layout directly from a load calculation: circuit numbers, breaker sizes, two-pole spans, and spare spaces, arranged the way a real panelboard is wired. Hand off into the full Panel Schedule editor to adjust circuit labels, phase assignment, or breaker sizes. PDF EXPORT Export any result as a PDF report for permit submission, job documentation, or client records.