AmpRule

Every number an electrician needs, with the code section that backs it up. AmpRule is the reference and calculator built the way the trade actually works: search finds what you mean, tables stay readable on a phone, and every answer shows its NEC citation so you can hand it to an inspector. WIRE SIZING - THE WHOLE RUN IN ONE TAP Enter the load. Get the conductor, breaker, equipment ground, minimum raceway, maximum length and actual voltage drop - each with its code reference. Termination temperature, small-conductor limits and next-size-up rules are handled, and the app tells you which rule drove the answer. SEARCH THAT ACTUALLY FINDS IT Type a section number (310.16), a task (wire size), or job-site slang (smurf tube, greenfield). No exact wording required. THE 310.16 TABLE, FIXED Copper and aluminum on a switch, so there are only four columns on screen - no sideways scrolling. The header stays put while you scroll. Tap any cell to read it big, then send it straight into a calculator. CALCULATORS - Wire sizing with OCPD, EGC, raceway and max length - Voltage drop - every limit from 1% to 5% at a glance - Conduit fill - mix sizes and insulation types freely, with jam-ratio check - Box fill - every allowance listed line by line - Derating - ambient and conductor count kept as two separate steps - Conduit bending - 90s, offsets, three-point saddles and kicks, marks measured from the free end with shrink already included - Motors - table full-load current, conductor, short-circuit protection, overload and starter size - Ohm's law and power, plus kVA / kW and power factor BUILT FOR THE JOBSITE Works fully offline. No account, no sign-in, no ads. Big controls for gloved hands. Fractions shown the way a tape measure reads them. SAVE AND SHOW YOUR WORK Name a calculation, save it, and export a PDF with the code citations - useful when an inspector asks. DAILY CODE QUESTION One question a day, with a real explanation and the article behind it. ALL NEC EDITIONS, UPDATES FREE 2017, 2020, 2023 and 2026 are built in. Switch editions from any calculator - the tables, the results and the cited section numbers all follow. NO SUBSCRIPTION. EVER. One purchase unlocks everything, including future NEC editions. Search, the 310.16 table, voltage drop and the daily question stay free. AmpRule is not affiliated with or endorsed by NFPA. NEC and National Electrical Code are trademarks of the National Fire Protection Association. Always verify with the edition adopted by your AHJ.