What electrical load calculation means
An electrical load calculation adds up a home's lighting, appliance and heating or cooling loads by the code method to see what size service or feeder it needs.
Also called load calc, service load calculation.
Where it matters on a electrical job
EV chargers, heat pumps and hot tubs all start with this question. A written load calc protects you when you tell a customer their panel can or cannot take the new load, and some inspectors ask to see it.
What the model code says
- Under the code's optional method, the first 10,000 volt-amperes count at 100 percent and the rest at 40 percent. (IRC 2021, Chapter 36)
Check which code edition your building department enforces for electrical load calculation before you quote.
What it costs
The electrical panel upgrade cost guide has the typical job at $2,150 and the usual range at $1,300 to $3,000. The guide shows its sources and what moves the price. The electrical load calculator prices a job line by line.
Work it out
- Free calculator: Electrical load calculator
- Cost guide: Electrical panel upgrade cost
- Licensing: Electrical license rules by state
- Tools, templates and guides: Free electrical resources
Sources: 2021 International Residential Code, Chapter 36, Services (ICC). Checked October 9, 2026.