WireCalc - NEC Wire Sizing

Size wire, check voltage drop, and review your electrical calculations with WireCalc for iPhone and iPad. Guided steps and clearly labeled inputs help you move from circuit details to results you can inspect, copy, save, and share. WIRE SIZING Enter your load, voltage, run length, and installation conditions to find a conductor recommendation. See whether adjusted ampacity or voltage drop determines the size, then expand the calculation to review the sizes checked. Includes the next conductor size and a grounding-conductor sizing hint. VOLTAGE DROP Calculate voltage loss in volts and percent for DC, single-phase, and three-phase circuits. Compare the result with your selected limit, including parallel conductor sets. AMPACITY Check a conductor's capacity or find a size for a target current. Review table ampacity, ambient-temperature and conductor-count adjustments, and the terminal temperature limit. CONDUIT AND BOX FILL Compare conductor area with allowed raceway fill, using up to 10 conductor groups with individual quantities. Review box-fill allowances and matching standard box volumes. EVERYDAY HELPERS Use Ohm's Law and the kW/horsepower-to-amps helper. Save calculations to local history, copy results, or share a summary using the system share sheet. WORKS OFFLINE Calculations run on your device. No account, ads, in-app purchases, or subscriptions. Temperatures default to Fahrenheit; choose Celsius in More > Settings. REFERENCE AID, NOT A CODE APPROVAL WireCalc uses reference tables based on NEC 2023 and standard formulas. Local adopted codes and installation requirements may differ. It does not perform a complete code analysis or account for every condition of use, and it is not a substitute for the current adopted code, manufacturer instructions, or a licensed electrician's judgment. Verify all results before installation. NEC is a registered trademark of the National Fire Protection Association. WireCalc is not affiliated with or endorsed by the NFPA.