Electrical Calculators for Professionals & Homeowners
Free, NEC-compliant wire sizing, voltage drop, power conversion, solar sizing, and energy cost tools. Built for electricians, engineers, and DIYers. Mobile-friendly. No sign-up required.
Wire & Cable Sizing
12 toolsNEC-compliant wire sizing, voltage drop, conduit fill, and ampacity tools
Power & Electrical
10 toolsOhm's law, watts/amps conversion, power factor, and 3-phase calculations
Energy Cost & Consumption
8 toolsElectricity costs, appliance running costs, and energy usage calculators
Solar & Renewable
7 toolsSolar panel sizing, ROI, battery bank, inverter, and charge controller tools
Lighting
5 toolsLumens, watts, lighting levels, and cost calculators
Circuit & Panel
7 toolsBreaker sizing, load calculations, grounding, transformers, and motor starters
Unit Converters
6 toolsQuick conversions between electrical and energy units
Browse Calculators by Category
400+ specialized pages — solar by state, EV charging by car, breaker sizing by appliance, electricity costs worldwide, and more.
☀️ Solar Calculator by State
State-specific solar panel sizing, costs, incentives & payback
All 51 States →💰 Electricity Cost by Appliance
Running cost per hour, day, month & year for 25 appliances
All 25 Appliances →🌍 Electricity Cost by Country
Rates, bills & comparisons for 20 countries worldwide
All 20 Countries →💡 Electricity Cost by State
Built for the Job Site
Every calculator is designed for mobile-first use. Get accurate, NEC-compliant results on your phone while you work. Bookmark your favorites for quick access on every job.