Wattson vs NEC Load Calculator

Stop guessing. Stop scrolling through ads. Stop paying monthly for a calculator. Wattson is two tools in one app: 15 precision electrical calculators with an AI assistant that actually runs them, and a project manager for your jobs — clients, photos, materials, estimates and payments. Built for electricians and engineers who work in the field, not the ones designing the app store. AI ASSISTANT — ANSWERS YOU CAN TRUST Other apps wrap a chatbot and call it AI. Wattson's AI runs your actual calculators — cable sizing with full derating, voltage drop, breaker coordination — and returns verified results citing the exact IEC or NEC code section. Not opinions. Math. Use voice input when your hands are full. Speak your question, get a verified answer — hands-free on the job site. PROJECT MANAGEMENT — EVERY JOB IN ONE PLACE • Clients — name, phone and address; tap to call or open in maps • Job status — active, completed or archived; search all your projects • Photos — before, after and progress shots; draw on photos to mark up the work • Notes — typed or by voice • Materials — quick-add common electrical parts, quantities and prices; export the list as PDF • Estimates — materials plus labor hours and rate; export a PDF to send to your client • Payments — cash, bank transfer or card; see quoted, paid, remaining and profit per job • Documents — keep files with the job • Sign in to back up your projects and sync them across devices SMART CABLE SIZING Full derating factor analysis (Ca, Cg, Ci) per IEC 60364 — installation method, conductor material, insulation type, ambient temperature, and grouped circuits. PRO CALCULATORS • Smart Cable Sizing — full derating factors • Voltage Drop — single-phase and 3-phase • Breaker Sizing — Ib ≤ In ≤ Iz protection coordination • Motor Calculator — FLC, starting current, protection • Short Circuit (Ik) — IEC 60909 fault current • Earth Fault Loop (Zs) — loop impedance testing • Power Calculator — P, Q, S, cos φ • Power Factor Correction — capacitor bank sizing • Wire Sizing — AWG and mm² with capacity tables • Conduit Fill — IEC fill limits • Box Fill — NEC 314.16 volume calculations • Dwelling Load — NEC Article 220 residential loads FREE — NO CATCH • Ohm's Law — V, I, R, P solver • Unit Converter — AWG, kW, HP, °C • LED Color Temperature • Wiring Color Codes — IEC 60446 standards • IP Rating Decoder — IEC 60529 • Installation Heights • Wiring Diagrams — 12 interactive circuit diagrams • Full AI assistant with voice input WIRING DIAGRAMS 12 professional interactive circuit diagrams — 6 for IEC and 6 for NEC. Color-coded wires per IEC 60446 and NFPA 70, component labels, installation notes, and regulatory references. Pinch to zoom, tap to explore. DUAL STANDARD SUPPORT Switch between IEC 60364 and NEC/NFPA 70 with one tap. Every calculation cites the applicable code section. Whether you wire to European or American standards — one app covers both. PDF REPORTS Export PDF reports for cable sizing, box fill, dwelling load, materials lists and estimates. Hand them to inspectors, clients, or keep them for your records. 8 LANGUAGES English, German, French, Spanish, Italian, Polish, Portuguese, and Croatian. The AI responds in your chosen language. NO ADS. NO SUBSCRIPTIONS. NO $10/MONTH "AI TAX." Download free with the free tools above, the full AI assistant and wiring diagrams. Unlock all Pro calculators and project management with a single purchase. No recurring fees. No ads. No paywalled NEC editions. Ever. WHY ELECTRICIANS SWITCH TO WATTSON → AI that runs real calculations, not a chatbot wrapper → Calculators and job management in one app → Estimates and payment tracking for every job → Voice input — hands-free on the job site → Full derating factors other apps skip entirely → IEC and NEC in one app — not two separate purchases → PDF reports for inspectors, clients and documentation → No ads, no subscription → 8 languages and dark mode Wattson. The electrical toolbox professionals trust.

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.