NEC-Compliant Electrical Calculators
Professional-grade electrical calculators built on NFPA 70 (NEC) standards — for US licensed electricians and DIY homeowners. Free, no signup required.
Choose a Calculator
All calculators use NEC/NFPA 70 standards and AWG wire gauges — no AU/NZS standards.
Calculate voltage drop (V and %) for any US circuit. NEC compliance badge included. Copper & aluminum, 120–480V.
Find the correct AWG wire gauge for your circuit. NEC 3%/5% voltage drop tolerance, NEC Table 310.15 ampacity.
Calculate energy usage in kilowatt-hours. Enter device wattage and hours — get daily, monthly, and yearly kWh instantly.
Estimate your monthly electricity bill. Enter kWh usage and rate — or select your state for the EIA 2024 average rate.
Calculate NEC conduit fill percentage by wire count and AWG gauge. EMT, IMC, Rigid, PVC Sch 40 & 80 supported.
Complete AWG wire gauge reference with NEC ampacity values for copper and aluminum conductors. NEC Table 310.15(B)(16).
Why NEC-Compliant Matters
🇺🇸 US NEC Standards Only
Our calculators reference NFPA 70 (National Electrical Code) — not AU/NZS standards used by some competitors. All wire gauges are in AWG, all voltages in US standard (120/240/277/480V).
🔒 No Vendor Bias
Unlike manufacturer-sponsored calculators, we have no financial relationship with wire or conduit vendors. Results reference only NEC code and standard formulas — no product upsell.
🔗 Shareable Calculations
Every calculator generates a shareable URL with your inputs encoded. Save it as a bookmark or send to a colleague — no login required, no account needed.