Electrical load calculations made easy
Stop using manual spreadsheets. Kopperfield is an electrical load calculation app for residential and commercial jobs, on the web and on iOS and Android. Use our free tool to get accurate results with an instant PDF report that helps finish inspections and close customers faster.
Complete accurate load calculations in minutes
Optional or standard method
Choose from either method and complete a load calc with pre-loaded common appliances and their output values
Residential and commercial calculations
Includes options to create both residential and commercial load calculations.
Calculations based on NEC rules
Utilizes default values from the 2017, 2020, 2023 and 2026 National Electrical Code, Article 220 (Article 120 in 2026), including values for EV chargers
Inspector-ready reports
Instantly generates a downloadable PDF printout of your calculation to share with inspectors or customers
Smart property data
Looks up the job address and surfaces property data including building square footage for easier calculations
Automatic demand factors
Detects and applies demand factors based on occupancy type for commercial calculations.
Kopperfield AI fills in your load calcs. Rolling out now. Tell it what to add, like a 48 A EV charger, or send a photo of the panel. The calculator does the math.
The Kopperfield tool helps with load calculations and avoids common mistakes, such as handling an EV charger in a load calc. I refer Kopperfield’s tool to contractors I work with.
Reina M, City Electrical Inspector
Supporting a variety of load calculation scenarios
Kopperfield supports commercial load calculations. Get started today and complete commercial load calcs with confidence.
Includes home generator sizing
Estimate generator sizing to determine what size generator you need in seconds. Adjust reserve margin and voltage dip to easily determine the right generator size for any residential project.
Get started with the mobile app
Download our app to create load calculations on the go using your iOS or Android phone or tablet
Load calculator demo
Hear it from a pro
See how Kevin from Bella Electric San Diego uses Kopperfield design tools to save time and close more customers.
Unlock unlimited load calcs
Our free load calculator is limited to 2 free uses. Get more out of your load calcs when you subscribe to one of our paid plans.
Electrical load calculation in 3 easy steps
Add property info
Enter the address of the job you’re working on and we’ll pull in the square footage to start the residential or commercial electrical load calculation.
Edit the list of appliances
We’ve pre-loaded a list of common appliances and standard output values. Simply check and adjust them to match what you see on the property.
Get your free, shareable PDF printout
Input your preparer’s information and we’ll generate a free PDF that you can attach to your inspection report.
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NEC chatbot
Get answers to your questions about the National Electrical Code
Electrical load calculation common questions
