NEC 2026 Load Calculations (Colorado)

NEC 2026 Load Calculations (Colorado)

Colorado journeyman candidates must be fluent in dwelling load calculations, and the NEC 2026 changes rules that stood for decades. Two headlines drive nearly every question on this topic: the dwelling lighting unit load dropped from 3 VA/sq ft to 2 VA/sq ft (120.41), and the calculation rules moved from Article 220 into Article 120 in Chapter 1 (General Requirements) — so 220.41, Table 220.55, and 220.83 are now 120.41, Table 120.55, and 120.83. This chapter builds the full picture: where the rules live, the two per-square-foot values, branch-circuit counting, demand factors, the optional method, and continuous loads.

Learning Objectives

1.1 Where Load Calculations Live in the NEC 2026

Load calculations for branch circuits, feeders, and services lived in Article 220 in Chapter 2 for decades. The NEC 2026 eliminates that article and moves the calculation rules into Article 120 in Chapter 1 — General Requirements. The move is structural, but several values changed along the way — most importantly the dwelling lighting unit load.

1.1.1 Old-to-new reference map

Not everything moved: the conductor and overcurrent-device sizing rules of the branch-circuit and feeder articles (e.g., 210.19 and 215.2) stay where they are and still handle continuous loads at 125% where applicable (Section 1.9), and the minimum-number-of-branch-circuits requirement still comes from 210.11(A). Exam questions deliberately include the old references — "Article 220 in Chapter 2," 220.83, 220.41 — as incorrect options. On the Colorado exam, "Article 120 in Chapter 1" is the location answer.

1.2 Two Unit Loads: 2 VA/sq ft and 3 VA/sq ft

The most tested concept in the NEC 2026 dwelling calculation is that two different per-square-foot values exist, and each has its own job. Confusing them produces the classic wrong answer.

1.2.1 Why the lighting value dropped to 2 VA

NEC 2026 drops the dwelling lighting unit load from 3 VA to 2 VA/sq ft because LED and other high-efficacy lighting draws far less power per square foot than the incandescent-era loads the 3 VA figure was designed to serve. Section 120.41 (formerly 220.41) anchors the calculation at the lower value.

1.2.2 Why the circuit-counting value stayed at 3 VA

The load reduction must not quietly reduce the number of circuits a dwelling is required to have: circuit count is about coverage, not service diversity. Section 120.13 therefore keeps dwelling branch-circuit loads at 3 VA/sq ft when counting circuits — intentionally separate from the 2 VA/sq ft value in 120.41. Ask for the lighting load? Use 2 VA/sq ft. Ask how many branch circuits? Use 3 VA/sq ft.

1.3 The General Lighting and Receptacle Load (120.41)

Section 120.41 sets the dwelling general lighting and general-use receptacle load at 2 VA per square foot. In the standard method this is the starting figure of the service and feeder calculation, and it is usually tested before any demand factor is applied:

General lighting and receptacle load = floor area (sq ft) × 2 VA/sq ft

1.3.1 Worked examples

Example 1 — 2,000 sq ft. Load = 2,000 × 2 = 4,000 VA before demand factors. Under NEC 2023 the same house produced 6,000 VA — exactly the obsolete-value distractor.

Example 2 — 2,400 sq ft. 2,400 × 2 = 4,800 VA (the old 3 VA/sq ft answer, 7,200 VA, is a wrong option).

Example 3 — 3,000 sq ft. 3,000 × 2 = 6,000 VA before demand factors (9,000 VA under prior editions).

1.3.2 Notes

Multiply the stated living area only — no garages or open porches. "Before demand factors" means the raw area × 2 VA product, not the post-demand value.

1.4 Small-Appliance and Laundry Loads in the Standard Method

The 120.41 lighting figure is not the only receptacle-type load in a dwelling calculation. The standard method adds allowances for the required small-appliance and laundry branch circuits before demand factors:

Each required small-appliance branch circuit and the laundry branch circuit contributes a 1,500 VA allowance; the group passes through the demand-factor step together. On this chapter's questions the tested figure is the 120.41 lighting load itself, but a full standard-method problem adds these allowances before demand factors.

1.5 Minimum Number of General-Purpose Branch Circuits (120.13)

A dwelling's general-purpose branch circuits are counted so the dwelling has enough of them. The count is a load-based rule:

1.5.1 Circuit capacities

1.5.2 Worked examples

Example 1 — 1,500 sq ft with 15 A circuits. Count load = 1,500 × 3 VA = 4,500 VA. Each 15 A, 120 V circuit supplies 1,800 VA, so 4,500 ÷ 1,800 = 2.5 — rounded up, the minimum is 3 circuits.

Example 2 — 5,500 VA lighting load with 15 A circuits. 5,500 ÷ 1,800 = 3.06 → 4 circuits (210.11(A), Article 120 method). Do not round down.

Example 3 — 3,000 sq ft with 20 A circuits. Count load = 3,000 × 3 VA = 9,000 VA; 9,000 ÷ 2,400 = 3.75 → 4 circuits — against a service load of only 6,000 VA at 2 VA/sq ft (120.41).

1.6 Demand Factors and the Shape of the Standard Method

A demand factor is a permitted reduction applied to a connected load because not all of it draws at once. The standard method groups a dwelling's loads and applies demand to each group:

1.7 Cooking Appliances and Table 120.55

A household electric range is not added to the feeder load at nameplate: its elements are thermostatically controlled and never all draw full power for long. NEC Table 120.55 (formerly Table 220.55) supplies the permitted demand. The table moved into Article 120 with the 2026 reorganization, but its values are unchanged.

The single-range rule tested: for one range rated not over 12 kW, the table permits a feeder demand of 8 kW.

Example. A household electric range rated 12 kW is served by a 120/240-volt branch circuit. The minimum feeder demand is 8 kW — not 12 kW (nameplate) and not 10 kW. Ranges above 12 kW step through the table's additional columns, and the table also covers multiple ranges, but 8 kW for a single range not over 12 kW is the anchor. Note that the table gives a feeder/service demand for the calculation; the branch circuit feeding the range is a separate sizing exercise.

1.8 The Optional Method for Dwelling Units (120.83)

NEC 2026 Section 120.83 (formerly 220.83) permits an optional method for dwelling units that is often simpler — and can yield a lower computed load — than the standard method.

1.8.1 When it applies

The optional method is permitted for a one-family dwelling when the total connected load is served by a single 120/240-volt or 208Y/120-volt feeder or service. If loads are split across services, or the voltage system differs, the method does not apply. (There is no electric-heat-only or mobile-home-only restriction — those are distractors.)

1.8.2 The calculation

The 8 kVA starting block is new: NEC 2023 started at 10 kVA; NEC 2026 Section 120.83 starts at 8 kVA. An answer offering "the first 10 kVA at 100%" is the pre-2026 value.

1.8.3 Worked example

A 2,400 sq ft one-family dwelling served by a single 120/240 V feeder: general lighting at 2 VA/sq ft (2,400 × 2 = 4,800 VA), two small-appliance circuits (3,000 VA), laundry (1,500 VA), and a 12 kW range at nameplate (12,000 VA) — total connected load 21,300 VA.

The optional method counts the 12 kW range at nameplate, then applies the heavy 40% factor to everything above 8 kVA — a realistic feeder demand without every standard-method table.

1.9 Continuous Loads and Section 120.5(E)

A continuous load is one where the maximum current is expected to continue for 3 hours or more — typically lighting, some motors, and long-running heating loads. Older editions figured continuous loads at 125% inside the calculation itself. NEC 2026 changes that:

The 125% requirement did not disappear — it moved into the sizing step. "Continuous loads are always calculated at 200%" and "continuous loads are ignored" are both wrong; the load calculation carries the actual load and the sizing rules absorb the 125%.

Sizing example. A feeder supplies a 30 A continuous load: the load calculation shows 30 A, but the feeder conductors need an ampacity of at least 30 × 1.25 = 37.5 A, with the overcurrent device rated accordingly.

Code Navigation

On the Colorado exam, calculation rules live in Article 120, Chapter 1 — a 220-series number in an answer choice is the pre-2026 reference. References such as 210.11(A), 210.19, and 215.2 did not move.

Common Exam Traps

Practical Field Points

Summary