Dwelling service load calculation
Calculated load of a house under the NEC 220.82 optional method, in amps at 240 V, against the service it has today.
Expert check pending. This tool shows its formula, cited sources and assumptions with every result, and it's included in its role plan. A qualified expert in this trade hasn't signed the method off yet, so check the result against your own code, engineer or supplier before you rely on it.
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- Your own numbers, worked out as often as you like
- The full service sheet you can print or save to My work
- 3 cited sources, linked, with the checks to make
- Every other tool for the same role, in the same plan
- A plain-words read of your result (a fuller AI read with the Bifrost AI add-on)
Included in these role plans
Example result · fictional numbers
What you get: service sheet
Worked out by this tool from its default inputs. Its role plan lets you run your own numbers, print the sheet and save it.
34,172 VA = 142.4 A at 240 V: fits the 200 A service at 71%, 57.6 A to spare
- General lighting and receptacles
- 6,000 VA (3 VA per sq ft)
- Small-appliance and laundry circuits
- 4,500 VA (1,500 VA each)
- Fixed appliances at nameplate
- 31,180 VA (cooking, dryer, water heater and others, EV charger)
- General load after demand
- 22,672 VA (first 10,000 VA at 100%, the other 31,680 VA at 40%)
- Heating (larger than cooling)
- 11,500 VA
- Calculated load
- 34,172 VA = 142.4 A at 240 V
Load calculation, line by line (NEC 220.82)
- General lighting and receptacles
- 2,000 sq ft × 3 VA = 6,000 VA
- Small-appliance and laundry circuits
- 3 × 1,500 VA = 4,500 VA
- Range, ovens and cooktops
- 12,000 VA nameplate
- Dryer
- 5,000 VA nameplate
- Water heater and other fixed appliances
- 6,500 VA nameplate
- EV charger
- 7,680 VA nameplate (32.0 A at 240 V)
and 5 more lines
Also on the sheet
- The service, the utility data and the panel · 6 lines, starting with “Existing 200 A service”
The plain-words read of this example
By the NEC 220.82 optional method this house calculates to 34,172 VA, or 142.4 A at 240 V. That fits the 200 A service at 71%. The heat is the larger of the heating and cooling loads, at 11,500 VA. A year of utility data puts the house plus the EV charger at 65.9 A (220.87).
3 cited sources
- NFPA 70, National Electrical Code (NEC) (National Fire Protection Association)
- NEC free access (read-only, free account) (National Fire Protection Association)
- Charging Electric Vehicles at Home (U.S. Department of Energy, Alternative Fuels Data Center)
Plus 5 step-by-step checks, a print layout and a link that reopens it with your numbers.