Electrical Calculators
Professional-grade voltage drop calculators for every application. Our tools follow NEC 2023 standards and use resistance values from Chapter 9 Table 8.
Full-Featured Calculators
AC Voltage Drop Calculator
Professional AC calculator with NEC Table 9 values, power factor, and conduit types.
DC Voltage Drop Calculator
Calculate voltage drop for DC circuits including solar PV and battery systems.
Wire Size Calculator
Determine the optimal wire size for your application based on load requirements.
Ampacity Derating Calculator
Apply ambient temperature correction and current-carrying conductor adjustment before final wire sizing.
Conduit Fill Calculator
Estimate raceway fill for common THHN/THWN-2 conductor groupings before you finalize conduit size and layout.
Motor Starting Voltage Drop Calculator
Compare normal-running and start-up voltage drop on motor circuits using AC impedance and inrush assumptions.
Voltage Unbalance Calculator
Calculate three-phase voltage unbalance from field readings and flag motor, feeder, and service-quality concerns.
DC Systems
AC Systems
Quick Wire Sizing Reference
| Wire Size | Copper Ampacity | Aluminum Ampacity | Typical Use |
|---|---|---|---|
| 14 AWG | 15A | - | Lighting circuits |
| 12 AWG | 20A | 15A | General purpose outlets |
| 10 AWG | 30A | 25A | Dryers, water heaters |
| 8 AWG | 40A | 30A | Ranges, EV chargers |
| 6 AWG | 55A | 40A | Large appliances, subpanels |
* Ampacity values based on NEC Table 310.16 at 60°C rating. Always verify with current NEC tables.
Additional Resources
References & Standards
- NFPA 70 - National Electrical Code (NEC) - Official NEC standards from NFPA
- Copper Development Association - Copper wire specifications and properties
- Aluminum Association - Aluminum conductor information
- IEEE Standards - Electrical engineering standards