AmpPrepTry a free lesson
Menu

Free calculator · 2026 and 2023 NEC

Residential Electrical Load Calculator

Enter the house and its appliances and get the service load in amperes by the NEC standard method, under the 2026 NEC (Article 120) or the 2023 NEC (Article 220), with each step and section shown.

Residential load calculator

Outside dimensions; leave out open porches and unfinished space
0 if there is no electric dryer
0 if there is no electric range
Volts × amps of the unit

Fastened-in-place appliances: water heater, dishwasher, disposal, well pump and the like (not the range, dryer, heat or air conditioning).

Blank if not known
NEC edition

128 A calculated service load, 30,675 VA

Next standard service rating: 150 A.

How it was worked out

  1. General lighting: 2,000 ft² × 2 VA = 4,000 VA (120.41). Small-appliance circuits 3,000 VA and laundry 1,500 VA at 1,500 VA each (120.52). Subtotal 8,500 VA. Demand (Table 120.45): first 3,000 VA at 100%, the next part up to 120,000 VA at 35% = 4,925 VA.
  2. Fastened-in-place appliances: 3 totaling 6,500 VA, fewer than four, so 100% = 6,500 VA (120.53).
  3. Dryer: the larger of 5,000 VA or the nameplate = 5,000 VA, 100% for one dryer (120.54).
  4. Range: one range of 12 kW (not over 12 kW) is 8 kW in Column C = 8,000 VA (Table 120.55).
  5. Heat or air conditioning, whichever is larger (they do not run together, 120.6): heat 0 VA, air conditioning 5,000 VA, so 5,000 VA (air conditioning).
  6. Largest motor: 25% of the air conditioner's 5,000 VA = 1,250 VA (120.50 and 430.24).
  7. Total: 30,675 VA ÷ 240 V = 127.81 A, rounded to 128 A (120.5(B)).

Code sections (2026 NEC): Article 120, Part III, and 120.5(B).

What this calculator does not account for

The installed design must follow the code edition your jurisdiction has adopted, its local amendments, and the authority having jurisdiction. Check every value in your own code book.

Residential load calculation: the standard method

A one-family dwelling service calculation by the standard method adds, in order: the general lighting load (floor area × 2 VA per square foot in the 2026 NEC), the small-appliance and laundry circuits at 1,500 VA each, the lighting demand factors, the fixed appliances, the dryer, the range, and the larger of the heat or the air conditioning. Divide the total by the voltage for the service amperes. In the 2026 NEC these rules are in Article 120, not the Article 220 that older study guides cite.

Dwelling general lighting load (2 VA/ft²)

The general lighting load covers all general lighting and the general-use receptacles in a dwelling. You do not count outlets; you multiply floor area by a unit load.

Where to look
Article 120 Part III, 120.41: 2 VA per ft² (22 VA/m²) for one-family, two-family and multifamily dwellings. It already includes the general-use receptacles (including bathroom and garage circuits), the outdoor and basement receptacles, and the required lighting outlets.

2026 trap
New 120.13 uses 3 VA/ft², but only to count how many lighting branch circuits are needed. The feeder and service figure in 120.41 is 2 VA/ft². Some 2023-edition material uses 3 VA/ft² for the service; for the 2026 exam, use 2.

Procedure

  1. Find the floor area by 120.5(C).
  2. Multiply by 2 VA/ft² (or 22 VA/m² for metric areas).

Worked example
A 1,650 ft² ranch home.

Most common mistake
Using 3 VA/ft² for a service calculation, or using the ft² value on an area given in m². Also do not add separate loads for ordinary receptacles; 120.41 already includes them.

Dwelling lighting demand factors

Not every light and receptacle in a home is used at once, so the combined general lighting, small-appliance and laundry load gets a tiered discount.

Where to look
Article 120 Part III, 120.45 and Table 120.45, the "Dwelling units" rows. The table has three tiers for dwellings: the first 3000 VA at full value, the next band up to 120,000 VA at a reduced percentage, and anything above that at a lower one. Read the percentages from the table.

Procedure

  1. Add general lighting (120.41) + small-appliance + laundry (120.52).
  2. Take the first 3000 VA at 100 percent.
  3. Take the part from 3001 to 120,000 VA at the second-tier percentage.
  4. Take anything over 120,000 VA at the third-tier percentage.
  5. Add the pieces.

Worked example
2,200 ft² home, two small-appliance circuits, one laundry.

Most common mistake
Applying 35 percent to the whole total instead of only the part above 3000 VA. Also, the demand factors are never used to count branch circuits.

One-family dwelling service: the standard method

This skill puts the dwelling pieces together. Annex D Example D1(a) is the code's own model.

Procedure

  1. General lighting: floor area × 2 VA/ft² (120.41).
  2. Add small-appliance and laundry circuits at 1500 VA each (120.52).
  3. Apply Table 120.45 to that sum.
  4. Fixed appliances: 75 percent if four or more qualify (120.53), else 100 percent.
  5. Dryer: nameplate or 5,000 VA (120.54).
  6. Range: Table 120.55 Column C plus any Note 1 increase.
  7. Heat or AC: the larger only (120.6, 120.51).
  8. 25 percent of the largest motor, usually the AC if it was kept.
  9. EVSE at nameplate or 7,200 VA (120.57).
  10. Add everything; divide by 240 V (or 208 V for a 208Y/120 3-wire feeder); round per 120.5(B).

Worked example
1,500 ft², 2 small-appliance, 1 laundry, 12-kW range, 5.5-kW dryer.

Most common mistake
Using 3 VA/ft², adding both heat and AC, or forgetting the 25 percent motor adder.

Sections to look up

All in the 2026 NEC, with the 2023 number where it is different. Open your own book to each one; this page explains the rules in its own words and does not reproduce the code.

2023 NEC and 2026 NEC

The load calculation rules moved from Article 220 to Article 120; most sections keep their number after the article (220.45 is now 120.45). See the full list on the Article 220 page.

The dwelling general lighting load for a feeder or service is 2 VA per square foot in 120.41. The 2023 NEC used 3 VA per square foot; in the 2026 NEC that figure survives only for counting branch circuits, in new 120.13.

The 2026 NEC also leaves detached garages out of the dwelling floor area (120.5(C)), counts electric vehicle charging equipment at its nameplate rating (120.57, with 7,200 W only when there is no nameplate; the 2023 rule took the larger of the two), and takes 100 percent of the first 8 kVA, not 10 kVA, in the optional method of 120.82.

Every exam-relevant change from the 2023 to the 2026 NEC

Practice questions

Work each one with your code book open, then check the answer.

  1. What is the general lighting and general-use receptacle load for a feeder serving a 2,100 ft² dwelling?

    • A. 6,300 VA
    • B. 2,100 VA
    • C. 4,200 VA
    • D. 7,200 VA
    Show the answer to question 1

    Answer: C. 4,200 VA

    120.41: 2 VA/ft² for a dwelling feeder or service. 2,100 × 2 = 4,200 VA.

    Reference: 120.41 (2026 NEC)

  2. The combined general lighting, small-appliance and laundry load of a dwelling is 10,500 VA. What is the demand load after applying Table 120.45?

    • A. 3,675 VA
    • B. 10,500 VA
    • C. 5,625 VA
    • D. 4,875 VA
    Show the answer to question 2

    Answer: C. 5,625 VA

    First 3,000 VA at 100% = 3,000. Remaining 7,500 VA at 35% = 2,625. Total 5,625 VA.

    Reference: 120.45; Table 120.45 (2026 NEC)

  3. A 1,800 ft² one-family dwelling has two small-appliance circuits, one laundry circuit, a 12-kW range and a 5-kW dryer. Service is 120/240 V, single-phase. What is the calculated service load in amperes (standard method, rounded per 120.5(B))?

    • A. 77 A
    • B. 88 A
    • C. 74 A
    • D. 91 A
    Show the answer to question 3

    Answer: C. 74 A

    Lighting 3,600 + 4,500 = 8,100, so demand 4,785 VA. Range (Column C) 8,000. Dryer 5,000. Total 17,785 VA ÷ 240 = 74.10, so 74 A.

    Reference: 120.40; 120.41; 120.45; 120.52–120.57; 120.6; Annex D, Example D1(a) (2026 NEC)

  4. A 1,850 ft² single-family dwelling is being calculated by the standard method. What general lighting load is used for the service?

    • A. 3,700 VA
    • B. 5,550 VA
    • C. 1,295 VA
    • D. 2,405 VA
    Show the answer to question 4

    Answer: A. 3,700 VA

    120.41: 1,850 ft² × 2 VA/ft² = 3,700 VA. Demand factors are a separate step.

    Reference: 120.41 (2026 NEC)

Common questions

What changed in the 2026 NEC load calculation?

The rules moved from Article 220 to Article 120. The dwelling general lighting load for a service is 2 VA per square foot in 120.41 (it was 3 VA in the 2023 NEC), an EV charger counts at its nameplate (7,200 VA only when there is none), and the optional method takes 100 percent of the first 8 kVA instead of 10 kVA.

Do I count both the heat and the air conditioning?

No. Heating and cooling do not run at the same time, so only the larger of the two is counted (noncoincident loads). The other is left out.

What is the difference between the standard and the optional method?

The standard method applies demand factors item by item: lighting through the demand table, fixed appliances at 75 percent when there are four or more, the dryer at 5,000 VA or its nameplate, the range from Column C. The optional method for one dwelling adds most loads together and takes 100 percent of the first part and 40 percent of the rest. This calculator uses the standard method.

What size service does a house need?

At least the calculated load, rounded up to a standard rating, and never less than 100 A for a one-family dwelling. The calculator shows both the calculated amperes and the next standard size.

How is a range figured in a load calculation?

One household range up to 12 kW counts as 8 kW (Column C of the range demand table). Over 12 kW, add 5 percent to the 8 kW for each kW or major fraction of a kW above 12.

Next step

Test yourself across the whole exam, or see how the course teaches a skill from the start. The course teaches this topic with the rest of the exam: a starting assessment finds what you need, each skill starts with a lesson, and review and timed practice exams check that it stays with you.

Take the free practice testTry a free lessonTexas exam guide

Other electrical calculators

Other exam topics

Last verified November 11, 2026.