Demand factor for four or more fixed appliances
In a standard-method dwelling load calculation, four or more fastened-in-place appliances rated ¼ hp or 500 W or more may be counted at 75% of their nameplate total. Cooking equipment, dryers, space heating, air conditioning and EV chargers are left out.
What the code requires
When calculating the load on a home's feeder or service with the standard method, the NEC allows a 75% demand factor on the combined nameplate ratings of four or more fastened-in-place appliances on the same feeder or service. Each appliance must be rated ¼ hp or more, or 500 W or more. This applies to one-family, two-family and multifamily dwellings.
Some appliances can never be part of this group: fastened-in-place cooking equipment, clothes dryers, space-heating equipment, air-conditioning equipment and, since 2023, electric vehicle supply equipment (EVSE).
On the job
- EV chargers are figured separately under 220.57, at 7,200 W (VA) or the nameplate rating, whichever is larger.
- Example: qualifying appliances totaling 8,400 VA count as 6,300 VA after the 75% factor.
- With fewer than four qualifying appliances, the factor does not apply and they are counted at full nameplate.
- The optional calculation in 220.82 handles fastened-in-place appliances differently, adding their nameplate ratings to the general loads instead of applying this 75% factor.
What changed in 2023
The 2023 NEC added electric vehicle supply equipment to the list of equipment that cannot use the 75% factor.
In California
For new construction, the 2025 CEC (625.1.1) also requires electric vehicle charging to comply with CALGreen, the California Green Building Standards Code.
Related sections
- NEC 220.57
- NEC 220.54: Electric clothes dryer load (5,000 VA minimum)
- NEC 220.55: Electric range and cooktop load calculations
- NEC 220.82: Optional load calculation for a single home
Where this comes from
- Leviton Captain Code 2023: 220.53 and 220.57
- Mark Earley, Electrical Contractor: More on 2023's Chapter 2 updates (Aug 15, 2022)
- LBNL: Low-power electrification, the NEC and building energy codes (Apr 18, 2024)
- Electrician U: Dwelling unit service load calculations, standard method (2023 NEC)
- Read the official NEC free at NFPA
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