Conductors, Conduit & Raceways
The core install chain: Table 310.16 ampacity, conductor sizing, voltage drop, derating and bundling adjustments, conduit and box fill, bending offsets, cable tray fill, pulling tension, support spacing and burial depth.
Wire Gauge Calculator
Find the minimum conductor size (AWG/kcmil) for any electrical load per NEC §310.16. Supports 60°C, 75°C, and 90°C ratings, continuous loads (125%), and parallel runs.
Open calculator NEC 2026 / 2023Voltage Drop Calculator
Calculate AC/DC voltage drop and select conductor size per NEC §210.19 and §215.2 recommendations (3% branch, 5% overall). Uses Chapter 9 Table 9 resistance.
Open calculator NEC 2026 / 2023Wire Ampacity Chart & Reference Lookup
Interactive NEC Table 310.16 & Table 310.17 wire ampacity chart with ambient temperature and conduit bundling adjustment calculators.
Open calculator NEC 2026 / 2023Conductor Derating Calculator
Calculate adjusted conductor ampacity when bundling more than 3 current-carrying conductors (§310.15(C)(1)) and correcting for elevated ambient temperatures (§310.15(B)(1)).
Open calculator NEC 2026 / 2023Conduit Fill Calculator
Calculate raceway fill percentage and minimum conduit size per NEC Chapter 9 Tables 1, 4, and 5. Supports EMT, IMC, RMC, PVC-40, PVC-80, ENT, FMC, and LFMC with mixed wire sizes.
Open calculator NEC 2026 / 2023Box Fill Calculator
Calculate electrical junction box and device box fill volume in cubic inches per NEC §314.16. Covers conductors, devices, internal clamps, studs, and grounding wires.
Open calculator NEC 2026 / 2023Pull & Junction Box Sizing Calculator
Determine minimum pull and junction box dimensions for conductors #4 AWG and larger per NEC §314.28. Covers 8× straight pulls, 6× angle pulls, and U-pulls.
Open calculator NEC 2026 / 2023Conduit Body & Mogul LB Calculator
Size standard and Mogul conduit bodies (LB, LL, LR, T, C), cubic inch volume for < #4 AWG, and 6×/8× rules for ≥ #4 AWG per NEC §314.28.
Open calculator NEC 2026 / 2023Conduit Bending Calculator
Calculate offset multipliers, shrink, 90° stub-up take-up, 3-point and 4-point saddles, rolling offsets, and 360° bend limits for EMT & RMC.
Open calculator NEC 2026 / 2023Cable Tray Fill Calculator
Calculate minimum cable tray width and allowable fill area for ladder, ventilated, and solid bottom trays per NEC Article 392 and §392.22.
Open calculator NEC 2026 / 2023Wire Pulling Tension Calculator
Calculate conduit wire pulling tension, bend multiplier, Sidewall Bearing Pressure (SWBP), and pulling grip limits per IEEE 576 & NEC Ch. 9.
Open calculator NEC 2026 / 2023Conduit & Cable Support Spacing Lookup
Lookup maximum support strapping intervals and distance from boxes for NM, MC, EMT, RMC, PVC, and FMC per NEC Chapters 3.
Open calculator NEC 2026 / 2023MC Cable Connector Spacing & Gutter Sizing
Calculate knockout center-to-center spacing for MC cable connectors, locknut clearances, and panel wire-bending gutters per NEC §330.30 & §312.6.
Open calculator NEC 2026 / 2023Tap Conductor Rules Calculator
Calculate 10-foot (1/10th ampacity) and 25-foot (1/3rd ampacity) feeder tap conductor sizing and termination protection per NEC §240.21(B).
Open calculator NEC 2026 / 2023Underground Duct Bank Ampacity
Calculate underground electrical duct bank ampacity, mutual heating derate factors, soil RHO, and conduit configurations per NEC Annex B.
Open calculator NEC 2026 / 2023Underground Burial Depth Calculator
Find minimum underground burial depth (cover) per NEC §300.5 Table 300.5. Covers Direct Burial (UF-B), Rigid Metal Conduit (RMC), PVC Schedule 40/80, residential GFCI circuits, and driveways.
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