NEC Solar & EV Calculator

NEC Solar & EV Calculator brings fast, code-accurate NEC 2023 calculations for solar and EV charging installations right to your phone — built for installers, electricians, and inspectors working in the field. FOUR ENGINEERING MODULES • PV String Sizing (NEC Article 690) Size PV string voltage and current, accounting for temperature correction and module specifications. • Rapid Shutdown Compliance (NEC 690.12) Check controlled conductor compliance for rapid shutdown requirements at a glance. • Interconnection — 120% Rule (NEC 705.12(B)(3)) Verify busbar interconnection limits for solar backfeed against the 120% rule. • EV Charger Circuit Sizing (NEC Article 625) Size branch circuits for EVSE (electric vehicle supply equipment) installations. FREE TO START PV String Sizing and Rapid Shutdown Compliance are free to use, no account or subscription required. UNLOCK PRO A one-time purchase unlocks all 4 modules plus unlimited PDF export for every module — no subscription, all future updates included. BUILT FOR THE JOB SITE • Clean, fast interface designed for quick lookups between tasks • PDF export for job documentation and inspection records • Light and dark mode support DISCLAIMER All calculations are provided for reference only. Results must be verified by a licensed electrician against the governing NEC edition and any local amendments before use in construction. This app is not a substitute for professional engineering judgment or local code compliance review.