Electric Master: NEC Panel

New: lay out the whole panel — breakers on the rail, wire it, name every circuit, then export a PDF schedule and parts list. Every answer names the code table it used.

Every answer names the code table it came from — 310.16, Chapter 9, 250.122, Article 220 — so you can check it, cite it to an inspector, and learn it. That is the whole point.

20 calculators and a full panel planner. All of it works with no signal, in a basement, on a roof, in a crawlspace.

NEW: PANEL PLANNER + ONE-LINE DIAGRAM Lay out the actual board on screen. Drag breakers, GFCI/AFCI devices, busbars and terminals onto the rail, wire them up, name every circuit. Then export a PDF with your logo: panel schedule, one-line diagram and a parts list, ready to hand over.

FREE, NO ACCOUNT, NO ADS

• VOLTAGE DROP — branch and feeder circuits, instant 3%/5% check
• AMPACITY — NEC Table 310.16 lookup, every size and insulation type
• GROUND WIRE — equipment grounding conductor per 250.122
• OHM'S LAW and POWER TRIANGLE
• THREE PHASE
• PANEL PLANNER — free to enter and draw, core devices included

PRO CALCULATORS

• WIRE SIZING — the right conductor for the circuit, accounting for voltage drop, ampacity and temperature
• CONDUIT FILL — EMT, IMC, RMC, PVC and flexible raceway
• CONDUIT BENDING — 9 bend types (offset, 3- and 4-point saddle, rolling offset, concentric, back-to-back, parallel offsets, matching centers), bender presets and an on-screen level
• BOX FILL — junction box sizing per Chapter 9
• DWELLING LOAD — service sizing per Article 220
• NON-DWELLING DEMAND — commercial load calculation
• SERVICE ENTRANCE — service and feeder sizing
• GROUNDING ELECTRODE — per 250.66
• DERATING — temperature and conduit-fill factors
• MOTOR — branch circuit protection per Article 430
• TRANSFORMER — overcurrent protection per Article 450
• FAULT CURRENT — available short-circuit current
• EV CHARGER — EVSE branch circuit and load
• SELECTIVITY — protective device coordination

FOUR CODES, ONE APP NEC 2023 and 2026 - CEC 2024 (CSA C22.1) - BS 7671 - DIN VDE 0100. The app picks the right one for your region, and you can switch any time. Nobody else carries all four.

PAY ONCE IF YOU WANT TO Every Pro calculator gives you free calculations first, so you can check the math against your own book before you decide. Then choose a one-time Lifetime purchase and never see a subscription again — or pay monthly if you prefer.

BUILT FOR THE TRUCK, NOT THE OFFICE

• 100% offline. No internet, no account, no sign-up.
• No ads. No tracking. No data collected.
• PDF reports with your company logo and licence number, US Letter or A4
• History with job names, side-by-side comparison, Siri Shortcuts, Home Screen widget

Not affiliated with, endorsed by, or sponsored by the NFPA, CSA Group or the IET. NEC and National Electrical Code are registered trademarks of the National Fire Protection Association, Inc. Always verify against the adopted code edition in your jurisdiction.

Terms: https://elly2504.github.io/electrocalc-pages/terms-of-use.html Privacy: https://elly2504.github.io/electrocalc-pages/privacy-policy.html