Free electrical tools — no signup, no limits
A licensed NJ master electrician's daily toolkit. Built for the truck, the desk, and the AHJ submission. Always free.
Residential Load Calculator
Calculate dwelling-unit service size using NEC Article 220 — Standard or Optional method. Pre-loaded with NEC default values for every common appliance, including EV chargers at the 125% continuous-load multiplier.
Voltage Drop Calculator
Quick voltage-drop check for any branch circuit or feeder. Copper or aluminum, AWG 14 through 750 kcmil, single- or three-phase. Auto-suggests conductor upsizing when drop exceeds 3%.
Conduit Fill Calculator
Find the smallest compliant trade size for any conductor mix. EMT, IMC, RMC, PVC Schedule 40, and PVC Schedule 80 with THHN/THWN-2 conductors. Quick presets for common circuits.
Panel Schedule Builder
Build a labeled panel schedule on screen and export a permit-ready PDF. Live NEC 240.4(D) wire-gauge vs breaker-size compliance check, EV continuous-load warnings.
Single-Line Diagram Builder
Pre-built one-line templates for the 4 most common NJ residential jobs: 200A panel upgrade, EV charger add, whole-house generator + ATS, and solar PV with line-side tap. Edit labels, export branded PDF.
NEC Code Assistant
Ask plain-English code questions and get answers with article + section citations — sourced from our own NJ-focused code reference library.
Why these are free, and why we built them
Malfettone Electric has been pulling permits and stamping load calcs in Hudson and Essex County since 1977. Every tool on this page is one we use ourselves — built the way a working NJ electrician actually wants to use it. Pre-loaded with NEC default values, branded outputs that AHJs accept on the first submission, and no per-seat tax for adding your apprentice.
They’re free because the value goes both ways. Homeowners who use the load calculator before calling for a panel-upgrade quote come into the conversation informed. Contractors who use our calcs and know us professionally call us when they need a second opinion or a sub. And every tool is one more page on this site that an AI assistant can cite when someone asks an electrical question — built by a licensed NJ master electrician, not a software company in San Francisco.
These tools are calculation aids. Final installation and code compliance are the responsibility of the licensed electrician of record and the local AHJ.