Electrical Load Calculation Worksheet
Fill in the house and get a numbered load worksheet with demand factors, NEC references and the service size, ready to print for the permit.
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One-family dwelling, NEC 2023 Article 220 Part III (standard method) and 220.82 (optional method), 120/240 V or 120/208 V single phase service. Existing homes, multifamily and commercial buildings use other parts of Article 220. Runs in your browser. Verify with your local code, your permit office and a licensed electrician before you install.
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How to fill in the Electrical Load Calculation Worksheet
- Under “Method on the worksheet” pick Standard or Optional. The other method stays in the comparison table below.
- Enter the “Living area” in ft² or m², measured from the outside of the dwelling. Leave out open porches and unfinished spaces that cannot be adapted for future use. Under the 2023 NEC garages are counted unless they are in that unfinished group; your local amendments may differ.
- Enter the “Small-appliance circuits” (at least 2) and keep “Laundry circuit” ticked if the house has one.
- Enter the nameplate “Electric range” in kW and the “Electric clothes dryer” in W. Leave 0 if they are gas.
- List “Fastened-in-place appliances”, one per line as name, watts: a water heater, dishwasher, disposal or built-in microwave.
- Add anything else at 100 % under “Other loads”, for example a hot tub, and the “EV charger” nameplate in W.
- Enter the air conditioner or heat-pump compressor VA, then choose the “Electric heating” type, its VA and the number of separately controlled units.
- Tick the 25 % largest-motor line for the standard method, and pick the “Service voltage”.
- Read the numbered worksheet and the service size. Use “Print / save as PDF” to keep the worksheet with your plans; your permit office sets its own form and acceptance.
The example buttons load a gas house, an all-electric house, a house with an EV charger, a baseboard-heated house and a small house. “Copy result” and “Copy link” keep the inputs.
How is the electrical load calculated for a house?
The standard method adds the general lighting load, 3 VA per ft² (NEC 220.41) plus 1,500 VA for each small-appliance circuit and 1,500 VA for laundry, and applies Table 220.45: the first 3,000 VA at 100 % and the rest at 35 %. Then it adds the other loads at their demand: fastened appliances at 75 % when four or more are 500 W or larger, the dryer at 5,000 VA or its nameplate, the range from Table 220.55, an EV charger at 7,200 VA or its nameplate, and the larger of heating and cooling. The optional method adds almost everything at nameplate, takes the first 10,000 VA at 100 % and the rest at 40 %, then adds the air conditioning or heating at its own percentage.
| 2,000 ft² house, 240 V | Standard method | Optional method (220.82) |
|---|---|---|
| General lighting and receptacles | 10,500 VA, demand 5,625 VA | 10,500 VA at nameplate |
| Appliances, dryer, range | 6,000 + 5,000 + 8,000 VA | 8,000 + 5,000 + 12,000 VA at nameplate |
| Air conditioning | 5,000 VA, plus 1,250 VA for the largest motor | 5,000 VA |
| Total demand | 30,875 VA | 25,200 VA |
| Current and service | 128.6 A, 150 A | 105 A, 125 A |
What does the worksheet show on each line?
Line, item, connected load in VA, demand factor, demand load in VA and the NEC 2023 section. The last lines give the current at your service voltage, the common service size (100, 125, 150, 200, 225, 320 or 400 A, never below 100 A under 230.79(C)) and the code minimum, the next standard rating of Table 240.6(A).
When does the worksheet not apply?
It is for a new one-family dwelling. An addition to an existing house can use 220.87 (measured load) or 220.83, apartments and commercial buildings use other parts of Article 220, and your jurisdiction may adopt a different NEC edition or add rules. Check what your permit office wants on the form.
Worked examples
| Input | Result |
|---|---|
| Standard method (Article 220 Part III), 2000 ft², range 12 kW, cooling 5000 VA | 30,875 VA, 150 A service |
| Optional method (220.82), 2000 ft², range 12 kW, cooling 5000 VA | 25,200 VA, 125 A service |
| Standard method (Article 220 Part III), 1500 ft², range 12 kW, cooling 0 VA | 18,600 VA, 100 A service |
| Standard method (Article 220 Part III), 2500 ft², range 12 kW, cooling 4500 VA | 48,455 VA, 225 A service |
| Optional method (220.82), 3200 ft², range 14 kW, cooling 7000 VA | 36,280 VA, 200 A service |
Calculated by the tool above; open it with the same values to see each step.
Questions, briefly answered
What is an electrical load calculation worksheet?
A form that lists the loads of a building, applies the demand factors of the code and ends with the total load and the size of the service. Permit offices ask for one to show that the service is large enough.
How do you do a residential load calculation?
Add general lighting (3 VA per ft²) and the small-appliance and laundry circuits, apply the Table 220.45 factors, add the appliances, dryer, range, EV and the larger of heating and cooling at their demand factors, then divide the total VA by the voltage.
Which is better, the standard or the optional method?
The optional method usually gives the smaller load because it counts the first 10,000 VA at 100 % and the rest at 40 %. In the default house it saves 5,675 VA, about 24 A. Both are allowed for a service of 100 A or more; your permit office may prefer one.
What is the 3 VA per square foot rule?
NEC 220.41 sets the general lighting and receptacle load of a dwelling at 3 VA for each ft² of floor area. Under 220.5(C) the area uses the outside dimensions and leaves out open porches and unfinished areas not adaptable for future use. In the 2020 NEC garages were also left out; the 2023 text no longer lists them, so this worksheet counts them. Local amendments may differ.
How many small-appliance circuits does a house need?
At least two 20 A kitchen and dining circuits, each counted at 1,500 VA, plus a laundry circuit at 1,500 VA. Enter more if the house has them.
How is the electric range counted?
By Table 220.55: one range over 12 kW up to 27 kW is 8 kW increased by 5 % for each kW above 12; a range between 8.75 kW and 12 kW is 8 kW. The worksheet shows the line.
Can I use this worksheet for a permit?
Permit offices set their own form and decide what they accept; some use a state or county worksheet. Print this one to keep your numbers and copy the lines onto the office’s form if it requires its own. It does not replace a permit review.
What service size does the load give?
The tool divides the demand VA by the service voltage and picks the next common rating. A calculated 128.6 A gives a 150 A service; the code minimum rating (Table 240.6(A)) is shown next to it.