NEC dwelling service-load calculation for single-family homes — both the optional (220.82) and standard (220.42/.52/.53) methods.
1 · Dwelling
2 · Fixed appliances (nameplate VA)
Enter each permanently connected appliance's nameplate rating in VA (watts). Leave 0 if you don't have it. Do not include heating or AC here.
3 · Heating / cooling (larger is used)
Calculated service load
| General connected load | — |
| After demand factor | — |
| HVAC (larger of heat/AC) | — |
This runs your choice of NEC dwelling-load method. The optional method (220.82) sums general loads (3 VA/sq ft + small-appliance, laundry, and fixed-appliance VA), reduces them by the demand factor (first 10 kVA at 100%, remainder at 40%), and adds the larger of heating or cooling. The standard method (220.42/.52/.53/.54/.55/.60) instead applies the graduated lighting demand factor and treats the range (Table 220.55), dryer (220.54), and fixed appliances (220.53, 75% if four or more) as separate line items. Both divide by service voltage; both apply to dwellings on a single 120/240V or 120/208V service of 100A or more.
For planning and verification only. A service-sizing calculation submitted for a permit must be prepared and verified by a licensed electrician against your equipment's actual nameplate ratings and your local code amendments. Results here are only as accurate as the values you enter. NEC® is a registered trademark of the NFPA; this tool is not affiliated with or endorsed by the NFPA.