Kopperfield vs NEC Load Calculator

Save time and money. Get ready for permits and projects with faster and easier design tools from Kopperfield, including load calcs, line diagrams, panel schedules, and more. Once logged into your Kopperfield account, you'll enjoy our: * Load calculator: Easy-to-use interface pre-loaded with common appliances and their standard output values from the National Electrical Code. Add information on the property and your calculation will automatically update. Supports both commercial and residential calculations, as well as the Standard (NEC Article 220 Part III), Optional (NEC Article 220 Part IV), and 2026 Standard (NEC Article 120 Part III) methods. * Single line diagram tool: Contains dozens of common templates and electrical symbols to make it easy to generate new diagrams and share them with your team. View diagrams from any device and create new templates on tablet or desktop for your whole team to use. * Panel schedules: Includes tools to complete panel schedules and create labels for electrical panels. Drag-and-drop interface makes it easy to arrange and customize circuits for both split-phase and three-phase projects. * NEC chatbot: Custom chatbot with advanced search capabilities to quickly reference specific sections of the 2017, 2020, or 2023 National Electrical Code. Includes the following features: * Fast PDF outputs: instantly generate a downloadable, one-page PDF report of your load calc, line diagram, or panel schedule to share with inspectors and customers * Smart property data: enter the property address and we’ll pull in the square footage for any customer project or electrical load calculation * AI panel photo processing: upload a photo of an electrical panel to automatically add items to your load calculation or panel schedule * Team dashboard: store your team's projects and documents in one place for easier management, access, and review *Single and three phase options: use a variety of nominal voltages for residential and commercial building types, including: 120/240V, 120/208V, 120/240V, 208Y/120V 3Ø, 240V 3Ø Delta, 240V 3Ø Hi-leg Delta, 347V 3Ø Delta, 480Y/277V 3Ø, 480V 3Ø Delta, 600Y/347Y 3Ø, 600V 3Ø Delta. * Standard scenarios: generate load calcs for scenarios including single family homes (standard and optional methods), multi dwelling units (i.e., duplex, triplex, quad), 120/208v (three-phase power) dwellings, accessory dwelling units and additions, commercial occupancy types, and heat pumps * Common appliance defaults: choose from a pre-loaded list of common appliances and standard output values that you can adjust for every load calculation * EV charger inputs: include EV charger values to any load calculation, essential for modern homes

NEC Load Calculator performs NEC 2023 load calculations for residential, commercial, motor, and branch circuit work — 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. 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. 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. 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.