What does a 200 A service load calculation look like, line by line?
Under the NEC 2023 standard method (Article 220 Part III), this 2,400 ft² all-electric house calculates to 44,755 VA, or 186.5 A at 240 V, so the minimum service is 200 A. The 220.82 optional method on the same house gives 33,722 VA (140.5 A, a 150 A minimum). The difference, 11,033 VA, is almost entirely how the two methods treat the heat pump’s strip heat and the general load. Both results are legitimate; the permit application states which method was used.
Updated September 23, 2026. Numbers on this page are computed by the same engine as the calculators, under NEC 2023.
Worked example: standard method on a 2,400 ft² all-electric house
Calculated per NEC 2023Standard method (Article 220 Part III)
Inputs
| NEC edition | NEC 2023 |
|---|---|
| Floor area | 2,400 ft² plus 480 ft² attached garage |
| Small-appliance circuits | 3 |
| Laundry circuits | 1 |
| Cooking | Electric range 12 kW |
| Clothes dryer | 5,500 VA |
| Appliances fastened in place | Electric water heater 4,500 VA; Dishwasher 1,200 VA; Garbage disposal 900 VA; Built-in microwave 1,500 VA; Garage door opener 600 VA |
| Heating | Heat pump compressor 4,800 VA with 10,000 VA supplemental strip heat |
| Air conditioning | None |
| Motors | Well pump 1,656 VA |
Result
| Calculated load | 44,755 VAfrom 62,096 VA connected |
|---|---|
| Calculated current | 186.5 Aat 240 V |
| Minimum service rating | 200 A240.6(A) standard rating, not less than 100 A |
| Feeder/service neutral (220.61) | 19,674 VA82.0 A |
| Line item | NEC | Connected | Demand | Basis |
|---|---|---|---|---|
| General lighting and receptacles | 220.41 | 8,640 VA | (in subtotal) | 2,400 ft² + 480 ft² attached garage (220.41) × 3 VA/ft² |
| Small-appliance branch circuits | 220.52(A) | 4,500 VA | (in subtotal) | 3 circuits × 1500 VA |
| Laundry branch circuit | 220.52(B) | 1,500 VA | (in subtotal) | 1 circuit × 1500 VA |
| General load after demand factors | Table 220.45 | 14,640 VA | 7,074 VA | 3,000 VA at 100% = 3,000 VA; 11,640 VA at 35% = 4,074 VA |
| Appliances fastened in place | 220.53 | 8,700 VA | 6,525 VA | 5 appliances at 75% (four or more, 220.53) |
| Clothes dryers | 220.54 | 5,500 VA | 5,500 VA | 1 × 5,500 VA (nameplate) at 100% (Table 220.54) |
| Cooking appliances | 220.55 | 12,000 VA | 8,000 VA | Column C for 1 unit = 8 kW |
| Electric space heating | 220.60 | 14,800 VA | 14,800 VA | Larger of heat pump 4,800 VA + supplemental heat 10,000 VA = 14,800 VA and cooling 4,800 VA; heating governs (220.60) |
| Air conditioning | 220.60 | 4,800 VA | 0 VA | Omitted, heating is the larger noncoincident load (220.60) |
| Motors | 220.50 / 430.24 | 1,656 VA | 1,656 VA | 1 motor at nameplate |
| 25% of largest motor | 220.50 / 430.24 | — | 1,200 VA | 25% of 4,800 VA (largest motor or compressor) |
| EV supply equipment | 220.57 | — | 0 VA | None |
| Other loads | 220.14 | — | 0 VA | None |
| 25% of continuous loads | 230.42(A)(1) | — | 0 VA | No continuous loads |
The general load is 14,640 VA of connected lighting and circuits, reduced by Table 220.45 to 7,074 VA. The heat pump and its 10 kW of supplemental heat (14,800 VA) is the largest single line; the 12 kW range drops to 8,000 VA under Table 220.55, and the five fastened-in-place appliances take the 220.53 75% factor (6,525 VA). Total 44,755 VA, 186.5 A: a 200 A service.
- The attached garage counts in the standard method’s lighting load under the 2023 wording of 220.41; the optional method excludes it under 220.82(B)(1).
- 25% of the largest motor (430.24) is taken on the heat pump compressor, which is larger than the well pump.
Same house under the 220.82 optional method
Calculated per NEC 2023Optional method (220.82)
Inputs
| House | Identical inputs; the 480 ft² garage is excluded from lighting by 220.82(B)(1) |
|---|
Result
| Calculated load | 33,722 VAfrom 55,856 VA connected |
|---|---|
| Calculated current | 140.5 Aat 240 V |
| Minimum service rating | 150 A240.6(A) standard rating, not less than 100 A |
| Lower method | optional by 11,033 VA46.0 A |
| Line item | NEC | Connected | Demand | Basis |
|---|---|---|---|---|
| General lighting and receptacles | 220.82(B)(1) | 7,200 VA | (in subtotal) | 2,400 ft² × 3 VA/ft² (480 ft² garage excluded, 220.82(B)(1)) |
| Small-appliance and laundry circuits | 220.82(B)(2) | 6,000 VA | (in subtotal) | 4 circuits × 1500 VA |
| Appliances fastened in place | 220.82(B)(3) | 8,700 VA | (in subtotal) | 5 at nameplate |
| Ranges, ovens and cooking units | 220.82(B)(3) | 12,000 VA | (in subtotal) | 1 at nameplate |
| Clothes dryers | 220.82(B)(3) | 5,500 VA | (in subtotal) | 1 at nameplate |
| Permanently connected motors | 220.82(B)(4) | 1,656 VA | (in subtotal) | 1 at nameplate |
| Other fixed loads | 220.82(B)(3) | — | (in subtotal) | None |
| EV supply equipment | 220.82(B)(3)a | — | (in subtotal) | None |
| General load after demand factors | 220.82(B) | 41,056 VA | 22,422 VA | First 10,000 VA at 100%; remaining 31,056 VA at 40% = 12,422 VA |
| Heat pump compressor at 100% plus supplemental heat at 65% | 220.82(C)(3) | 14,800 VA | 11,300 VA | 100% of 4,800 VA + 65% of 10,000 VA = 11,300 VA; largest selection |
| Air conditioning and cooling | 220.82(C)(1) | — | 0 VA | None |
The optional method puts everything but heating and cooling into one general load, takes the first 10,000 VA at 100% and the rest at 40%, then adds the heat pump under 220.82(C)(3): compressor at 100% plus 65% of the supplemental heat. That is where the 11,033 VA goes.
Reading the standard-method table
Rows marked "in subtotal" are components: the lighting load, the small-appliance circuits and the laundry circuit are added together and then reduced once by Table 220.45, so only the "General load after demand factors" row counts toward the total. Everything below it counts directly.
Heating and cooling are noncoincident loads under 220.60, so only the larger of the two is carried. With a heat pump the comparison is the compressor plus supplemental heat against the cooling nameplate; here heating wins by a wide margin and the cooling row shows zero demand.
The 25% largest-motor adder from 430.24 and the 25% continuous-load adder from 230.42(A)(1) are separate rows so an inspector can see what they were taken on. This house has no continuous loads; an EV charger would add one.
Which method to file
The optional method (220.82) is available for a single dwelling served by a 120/240 V or 208Y/120 V 3-wire service of 100 A or more. Where its result is lower, as it is here, it is the usual choice for new construction because it can keep a house on a smaller service. The standard method is always available and is the fallback for anything 220.82 does not cover, including multifamily feeders and services under 100 A.
On this house the standard method calls for 200 A and the optional method for 150 A. Most contractors would install 200 A regardless: the conductor and panel cost difference is small, and it leaves room for an EV charger.
What the report should show
A reviewer wants to see the inputs (floor area, appliance nameplates, heating and cooling ratings), each line with its clause, the demand factor applied, the total in VA and amps, and the neutral. The Pro load calculator prints exactly this table and adds the panel schedule as a second section of the permit packet.
Frequently asked questions
- Why does the garage count in one method and not the other?
- NEC 2023 revised 220.41 so the standard method’s lighting load includes the attached garage area; 220.82(B)(1) still excludes it for the optional method. The calculator applies each rule to its own method.
- Do I use the range nameplate or the Table 220.55 value?
- The table. One 12 kW range takes Column C for one unit, 8 kW, so 12,000 VA of nameplate becomes 8,000 VA of demand. Ranges over 12 kW add 5% per kW above 12 (Note 1).
- Is 214 A of calculated load on a 200 A service ever acceptable?
- No. If the standard method exceeds 200 A the service must be the next standard rating up, or the optional method must be used and documented if it applies and comes in lower.
- What about the neutral?
- 220.61 sizes the neutral on the loads that actually return on it: the general load, cooking and dryers at 70%, and 120 V appliances. Here that is 19,674 VA, well under the ungrounded conductors.
Related questions
- What changed in dwelling load calculations between NEC 2023 and NEC 2026?One 2,200 ft² house calculated under both editions and both methods: Article 220 becomes 120, lighting drops to 2 VA/ft², the 125% continuous adder goes, EVSE moves to nameplate, and the optional method’s tiers change.
- 100 A vs 200 A service: which one does my house need?The same 1,600 ft² house calculated three ways under NEC 2023: gas appliances, all-electric, and all-electric with an EV charger. The optional and standard methods both shown, with the minimum service each requires.
More for electricians: NEC 2023 load calculations you can hand to an inspector · all answers