Engineering Calculators
These free electrical engineering calculators are built for practicing engineers, electrical contractors, solar installers, and engineering students who need quick, reliable calculations in the field or at the desk. Each tool follows established industry standards including the National Electrical Code (NEC), the Canadian Electrical Code (CEC), and standard engineering formulas used in power systems design.
Every calculator is designed and maintained by Ali Mazloum, P.Eng. (AB, NS), P.E. (TX), PMP — a licensed professional electrical engineer with hands-on experience in commercial and industrial electrical construction, renewable energy systems, and project management. The tools are free to use and require no registration or downloads.
Select a calculator below to get started. Each tool includes input validation, real-time results, the underlying formulas, and educational content explaining the engineering theory.
Disclaimer: These calculators are intended for educational and preliminary estimation purposes only. Results should not be used as a substitute for professional engineering design. Always consult a licensed electrical engineer before making decisions that affect safety, code compliance, or construction.
Voltage Drop Calculator
Calculate voltage drop and minimum conductor size for AC/DC circuits per NEC/CEC requirements. Supports copper and aluminum from 14 AWG to 500 kcmil.
Open CalculatorSolar PV Estimator
Estimate system capacity, annual energy production, and cost savings for rooftop solar arrays based on location, roof area, and electricity rates.
Open CalculatorWind Energy Calculator
Calculate turbine power output and annual energy production based on wind speed, rotor dimensions, and turbine efficiency. Includes Betz Limit validation.
Open CalculatorNEC Load Calculator
Perform NEC 220 residential service load calculations with demand factors, range demand per Table 220.55, and minimum service sizing.
Open CalculatorConstruction Cost Estimator
Generate a Class 5 conceptual cost estimate with trade-by-trade breakdown for 16 building types across all 50 US states. Includes quality and location adjustments.
Open Calculator