Last updated: November 10, 2026
Main pages
Electrical Calculations
Basic Electrical Math
AC Power & Power Quality
Measurements & Test Calculations
Transformer Calculations
- Control Transformer Load Calculator
- Transformer Current and Overcurrent Protection Calculator
- Transformer kVA Sizing Calculator
- Buck-Boost Transformer Calculator
- Transformer Turns Ratio Calculator
- Transformer Tap Voltage Calculator
- Transformer Voltage Regulation Calculator
- Transformer Efficiency and Loss Calculator
- Open-Delta Transformer Capacity Calculator
Conductors & Raceway
Conductor Sizing & Voltage Drop
- Conductor Ampacity Calculator
- Branch Circuit Conductor and Breaker Check
- Copper vs Aluminum Wire Cost Calculator
- Feeder Conductor Sizing and Voltage Drop Calculator
- Voltage Drop and Wire Size Calculator
- Wire Resistance Calculator
- Wire Power Loss Calculator
- Parallel Conductor Sizing Calculator
- Feeder and Branch Circuit Voltage Drop Calculator
Grounding & Bonding
Raceway Fill & Layout
- Cable Tray Fill and Ampacity Worksheet
- Conduit Bend Calculator
- Conduit Offset Calculator
- Three-Point Saddle Calculator
- Four-Point Saddle Calculator
- Stub-Up Bend Calculator
- Rolling Offset Calculator
- Back-to-Back Conduit Bend Calculator
- Kick Bend Calculator
- Parallel Conduit Offset Calculator
- Segmented Conduit Bend Calculator
- Conduit Fill Calculator
- Raceway Fill and Ampacity Calculator
Boxes & Cable Pulling
Wiring & Devices
Loads & Services
Service & Load Calculations
- Commercial Feeder and Service Load Calculator
- Multifamily Dwelling Load Calculator
- Household Range Demand Calculator
- Household Dryer Demand Calculator
- Fixed Appliance Demand Calculator
- Heating and Cooling Noncoincident Load Calculator
- Commercial Kitchen Equipment Demand Calculator
- Commercial Receptacle Load Calculator
- Commercial Lighting Load Calculator
- Panel Phase Load Balance Calculator
- Continuous Load Circuit Capacity Calculator
- Dwelling Load Calculator
- Existing Service Capacity Calculator
EV & Renewable Systems
Jobsite Power & Estimating
Generation & Lighting
Equipment & Systems
Motor Systems
- Multiple Motor Feeder Calculator
- Motor Speed and Slip Calculator
- Motor Starting Current Calculator
- VFD Motor Speed Calculator
- Motor Full-Load Current and Circuit Protection Reference
- Motor Overload Protection Setting Reference
- Motor Energy Cost Calculator
- Motor Efficiency Upgrade Payback Calculator
- Pump and Fan Speed Energy Calculator
- Motor Voltage Drop Estimator
- Three-Phase Motor Power and Torque Calculator
- VFD and Motor Compatibility Worksheet
Low-Voltage & Communications
Protection & Safety
- Arc-Flash Label Data Helper
- Available Fault Current and SCCR Screen
- Protective Device Time-Current Curve Comparison Calculator
- Energy Control Checklist Builder
- GFCI and AFCI Requirement Finder
- Standard Overcurrent Device Rating Calculator
- Equipment SCCR Comparison Calculator
- Ground-Fault Loop Current Estimator
Industrial & Emergency Systems
- Emergency Lighting Runtime Screen
- Emergency Lighting Illumination Calculator
- Industrial DC Power Supply Sizing Calculator
- Redundant DC Power Supply Capacity Calculator
- Control Panel Heat Load Calculator
- Enclosure Ventilation Airflow Calculator
- Enclosure Cooling Capacity Calculator
- Welding Circuit Sizing Calculator
- Industrial Enclosure Environment Reference
References
- All electrical references
- Panel Directory and Circuit Label Templates
- Wire and Cable Markings Reference
- U.S. Wire Color Codes and Identification
- Conduit Dimensions: EMT, IMC, RMC and PVC
- Conduit Bending Multipliers and Marking Guide
- Single-Pole, 3-Way and 4-Way Switch Diagrams
- Contactor and Relay Terminal Markings
- Electrical Test Record Templates
- Electrical Schematic Symbols and Abbreviations
- AWG, kcmil and Square Millimeter Size Chart
- Electrical Job Card and Handover Template
- NEC Edition and Local Code Adoption Guide
- Terminal and Wire Connector Markings Guide
- Circuit Breaker Markings and Compatibility Guide
- Conduit Knockout and Punch Size Chart
- Electrical Box Types, Dimensions and Volume Marks
- How to Read a NEMA Motor Nameplate
- GFCI LINE and LOAD Reference Diagrams
- RJ45 T568A and T568B Pinout Reference
- CAT Ratings for Meters, Probes and Test Leads
- Fuse Classes, Markings and Holder Compatibility
- NEMA Motor Frame Dimensions and Mounting Reference
- Transformer Nameplates and H/X Terminal Markings
- PoE Types, Classes and Power Reference Tables
- SPD Types and Surge Protector Nameplate Markings
- Lighting Control Interfaces: Phase, 0–10 V and DALI
- IP Ratings and NEMA Enclosure Type Differences
- U.S. Electrical Supply Systems and Voltage Diagrams
- Grounding, Bonding and Neutral Reference Diagrams
- CT and PT Polarity and Terminal Markings
- Two-Wire and Three-Wire Motor Control Diagrams
- NPN, PNP and Two-Wire Sensor Output Reference
- RS-485 and Modbus Serial Wiring Reference
- HVAC Nameplate MCA and MOCP Markings Guide
- PV Connector and DC Component Markings Reference
- SOOW, SJOOW and SJTW Flexible Cord Reference
- CMP, CMR and Low-Voltage Cable Fire Ratings
- UL Listed, Recognized and Classified Marks Guide
- Electrical Firestop System Lookup and Record Guide
- 4–20 mA Loop Wiring: Two, Three and Four Wires
- Contactor AC-1, AC-3 and AC-4 Utilization Categories
- Constant-Current and Constant-Voltage LED Drivers
- EV Charging Connectors: J1772, CCS1 and J3400
- UPS Topologies and Static vs Maintenance Bypass
- Cable Schedule and Endpoint Register Template
- Raceway Connectors, Couplings and Fitting Markings
- Ethernet Permanent Link, Channel and Test Reports
- Fiber Connectors: LC, SC, UPC and APC Identification
- Motor Lead Markings and Connection Diagram Reading Guide
- VFD Terminal Functions: Power, Motor, Control and STO
- Timer Relay Functions and Timing Diagrams
- Fail-Safe and Fail-Secure Access-Control Locks
- LED Tube Type A, B and C Compatibility Reference
- Generator Transfer Neutral and Bonding Document Review
- U.S. Thermocouple Types, Polarity and Color Codes
- RTD Two-, Three- and Four-Wire Connections
- 70 V and 100 V Speaker Transformer Tap Reference
- Fire Alarm IDC, SLC and NAC Circuit Identification
- PV Module and Inverter Data Sheet Reading Guide