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• Added Voltage Drop for single-phase and three-phase circuits. • Added Conduit Fill for EMT and PVC, with mixed conductor sizes and minimum-size suggestions. • Try one calculation free across the calculator suite; NEC Pro unlocks unlimited use and sharing. • Simplified conductor entry and the empty Box Fill result panel. • Corrected entering-ground volume allowances when more than four grounds enter a box. • Improved subscription product loading and access recognition.
NEC Box Fill Calculator brings three focused tools to your iPhone: Box Fill, Voltage Drop, and Conduit Fill. Enter your job details, get a clear result, and check the assumptions and NEC references behind it. TRY ONCE FREE One completed calculation is included across the three tools. Choose a tool, enter your values, and tap Calculate once free. Your result stays available to read. Additional calculations, input changes after the free result, and sharing require an auto-renewable NEC Pro subscription. BOX FILL Check required and available box volume, see PASS, TIGHT, or FAIL, and find the smallest suitable box in the included catalog. Supports conductor allowances, device yokes, internal clamps, support fittings, and entering equipment grounds under the supported NEC 2023 rules. A calculation breakdown shows where each allowance comes from. VOLTAGE DROP Estimate voltage drop in volts and percent, voltage at the load, and a wire-size suggestion for a 3% target. Supports single-phase and three-phase circuits with copper or aluminum conductors. Suggestions address voltage drop only; ampacity must be checked separately. CONDUIT FILL Check mixed THHN conductor sizes in EMT, PVC Schedule 40, or PVC Schedule 80. See fill percentage, the applicable conductor-count limit, and a minimum raceway size from the included catalog. NEC PRO Monthly and yearly auto-renewable subscriptions unlock unlimited live calculations with all three tools and result sharing. Prices and any eligible introductory offer are shown before purchase. Payment is charged to your Apple Account. Subscriptions renew automatically unless canceled before renewal. Manage or cancel in Apple Account settings. Restore Purchases is available inside the app. BUILT FOR THE JOB SITE Calculations run on your device and work offline. No account required and no ads. Limited app usage analytics help improve the product; calculator input values and numeric results are not uploaded. CODE EDITION AND SCOPE This release uses NEC 2023 references. The tools cover the options shown in the app and are not a complete installation or code-compliance assessment. Verify conductor ampacity, adopted code edition, local amendments, and AHJ requirements. NEC and National Electrical Code are registered trademarks of NFPA. This app is not affiliated with or endorsed by NFPA. Privacy Policy: https://autumn-jackrabbit-155.notion.site/3a4c2750335a8037a91ed5e6c277574d Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/